Ami E. Berkowitz

Research Professor; In memoriam (1926-2016)

Ami E. Berkowitz
Dr. Berkowitz's research was based on thin film and fine particle phenomena related to magnetic recording. It involved production of these materials and characterization of their microstructural, magnetic, and transport properties. Some research activities included:
  • Giant magnetoresistance and magneto-impedance
  • Antiferromagnetic oxides for MR head biasing
  • Magnetic viscosity phenomena
  • New particulate and film media
  • Finite size effects
  • Magnetic surface behavior

Ami Berkowitz received his Ph.D. in physics from the University of Pennsylvania in 1953. He was employed by the Franklin Institute Laboratories in Philadelphia from 1947 to 1960 where he was manager of the Magnetism and Thermoelectricity Division. He was with IBM from 1960 to 1968 initially at the Research Laboratory at Yorktown Heights, NY, and then as manager of the Materials Branch at the Components Division in Burlington, VT. From 1968 to 1986, Dr. Berkowitz was at the General Electric R&D Center in Schenectady, NY. There, he was active in electron beam addressed memories, thermomagnetic recording, magnetic tagging, magnetic printing, magnetic surface phenomena, amorphous and crystalline particles, and the development of spark erosion method for particle production.

In 1986, he came to UCSD as an Endowed Chair Professor in the Physics Department, and to CMRR to establish the materials group. At present, he is a Research Professor at CMRR and the Physics Department. Dr. Berkowitz has published extensively in the scientific and patent literature and with E. Kneller co-edited "Magnetism and Metallurgy", published by Academic Press. He has also given many invited talks, and has been twice appointed a Distinguished Lecturer for the IEEE Magnetics Society, and effective January 1997, he was elected to fellowship status in the American Physical Society.

1953 - 1970

  1. "The Approach to Saturation in Dilute Ferromagnetics", A. D. Franklin and A. E. Berkowitz. Physical Review, 89, 1171 (1953). [PDF UCSD only]
  2. "Diffusion of 60Co in Some Ni-Al Alloys Containing Excess Vacancies", A.E. Berkowitz, F.E. Jaumot, Jr., and F.C. Nix. Physical Review, 95, 1185 (1954). [PDF UCSD only]
  3. "Relation of Diffusion Measurements of Some Beta-Ray Absorption Phenomena", A.E. Berkowitz. Journal of Applied Physics, 26, 403 (1955). [PDF UCSD only]
  4. "Magnets: There's Untapped Strength in Pure Iron Powder", F.E. Jaumot, Jr. and A.E. Berkowitz. Iron Age (1956).
  5. "Magnetic Properties of Some Iron and Iron OxideMicropowders", R.B. Campbell, A. Amar, P.J. Flanders and A.E. Berkowitz, Proc. Conf. Magnetism & Magnetic Materials. Boston, MA,p. 118 (1956). [PDF UCSD only]
  6. "Magnetic Measurements of a Ni-Au Alloy", A.E. Berkowitz and P.J. Flanders, Proc. Conf. Magnetism & Magnetic Materials. Boston, MA, pp. 275, (1956).
  7. "Phase Transformations in Iron Platinum Alloys Near the CompositionFe3Pt", A.E. Berkowitz, F.J. Donahue, A.D. Franklin and R.P. Steijn, Acta Metallurgica, 5, 1 (1957) . [PDF UCSD only]
  8. "Magnetic Properties of Some Precipitating Systems", A.E. Berkowitz and P.J. Flanders. Journal of Applied Physics, 29, 314 (1958). [PDF UCSD only]
  9. "Magnetic Properties of Some Ferrite Micropowders", A.E. Berkowitz and W.J. Schuele. Journal of Applied Physics, 30, 1345 (1959). [PDFUCSD only]
  10. "Magnetic Analysis of the Precipitation of Iron from Beta Brass", A.E. Berkowitz and P.J. Flanders, Acta Metallurgica, 8, 823 (1960). [PDFUCSD only]
  11. "Interactions Between Ni and NiO", A.E. Berkowitz and H.J. Greiner. Journal of Applied Physics, 35, 925 (1964) . [PDF UCSD only]
  12. "New Ferromagnetic 5:2 Compounds in the Rare-Earth-Palladium Systems", A.E. Berkowitz, F. Holtzberg, and S. Methfessel, Journal of Applied Physics, 35, 1030 (1964). [PDF UCSD only]
  13. "Exchange Anisotropy and Strain Interactions in the Ni-NiO System", A.E. Berkowitz and J.H. Greiner. Journal of Applied Physics, 36, 3330 (1965). [PDF UCSD only]
  14. "Properties of Single Crystal CoO Films on MgO", J.H. Greiner, A.E. Berkowitz, and J.E. Weidenborner. Journal of Applied Physics, 37, 2149 (1966). [PDF UCSD only]
  15. "Influence of Crystallite Size on Magnetic Properties ofAcicular-Fe2O3 Particles", A.E. Berkowitz, W.J. Schuele and P.J. Flanders. Journal of Applied Physics, 39, 1261 (1968). [PDF UCSD only]
  16. "Magnetism and Metallurgy", 2 vols. ed. by A.E. Berkowitz and E. Kneller. Academic Press (1969).
  17. "Constitution of Multiphase Alloys", A.E. Berkowitz. Chapter VII, Magnetism and Metallurgy, Vol. 1. Academic Press (1969).
  18. "Anisotropy Modifications and Domain-Wall Behavior in Grooved Films", A.E. Berkowitz, W.J. Schuele, and K.R. Morey. IEEE Transactions on Magnetism, MAG-6, 130 (1970).

1971 - 1980

  1. "An Electron Beam-Magnetic Film Memory System", A.E. Berkowitz, W.C. Hughes, J.L. Lawson and W.H. Meiklejohn. Proceedings of 11th Symposium in Electron, Iron and Laser Beam Technology. Boulder, CO (1971).
  2. "Superparamagnetic Ferrite Particles Produced by Milling", A.E. Berkowitz and J.A. Lahut. American Institute of Physics Conference Proceedings, 10, 966 (1973).
  3. "Thermomagnetic Recording: Physics and Materials", A.E. Berkowitz and W.H. Meiklejohn. IEEE Transactions on Magnetism, MAG-11, 996 (1975). [PDF UCSD only]
  4. "Magnetic Tagging", A.E. Berkowitz, J.A. Lahut, W.H. Meiklejohn and C.E. VanBuren. IEEE Transactions on Magnetism, MAG-22, 1576 (1975). [PDF UCSD only]
  5. "Spin Pinning at Ferrite-Organic Interfaces", A.E. Berkowitz, J.A. Lahut, I.S. Jacobs, L.M. Levinson and D.E. Forester. Physical Review Letters, 34, 594 (1975). [PDF UCSD only]
  6. "Thermomagnetic Behavior on a Duplex Ferromagnetic Alloy", A.E. Berkowitz, J.D. Livingston, B.D. Nathan and J.L. Walter. Journal of Applied Physics, 50, 1754 (1979). [PDF UCSD only]
  7. "Magnetostatic Interactions in a Duplex Ferromagnetic Alloy", J.D. Livingston, A.E. Berkowitz, and J.L. Walter. IEEE Transactions on Magnetism, MAG-15, 1295 (1979). [PDF UCSD only]
  8. "Preparation of Amorphous Metal Powders by Spark Erosion", A.E. Berkowitz and J.L. Walter, in Rapid Solidification Processing, II, ed. by R. Mehrabian, B.H. Kear and M. Cohen. Claitor's Publication Division, Louisiana, p. 294 (1980).
  9. "Properties of Magnetic Fluid Particles", A.E. Berkowitz, J.L. Lahut and C.E. VanBuren. IEEE Transactions on Magnetism, MAG-16, 184 (1980). [PDF UCSD only]

1981 - 1990

  1. "Magnetic Properties of Amorphous Particles Produced by Spark Erosion", A.E. Berkowitz, J.L. Walker and K.F. Wall. Physical Review Letters, 46, 1484 (1981). [PDF UCSD only]
  2. "Magnets (Permanent) and Magnetostatics", A.E. Berkowitz, inEncyclopedia of Physics, ed. by R.G. Lerner and G.L. Trigg. Addison-Wesley Publishing Co., Reading, MA (1981).
  3. "Structure and Property Changes During Ion Bombardment of Crystalline Fe75B25", A.E. Berkowitz, W.G. Johnston, A.Mogro-Campero and J.L. Walter, in Metastable Materials Formation by Ion Implantation, ed. by S.T. Picraux and W.J. Choyke. Elsevier Science Publishing Co., Inc. (1982).
  4. "Amorphous Particles Produced by Spark Erosion", A.E. Berkowitz and J.L. Walter. Materials Science and Engineering, 55, 275 (1982). [PDF UCSD only]
  5. "A High Speed Magnetic Printer", A.E. Berkowitz, J.A. Lahut, W.H. Meiklejohn, R.E. Skoda and J.M. Wang. IEEE Transactions on Magnetism, MAG-18, 1796 (1982). [PDF UCSD only]
  6. "Atomic Structure of Amorphous Particles Produced by Spark Erosion", S. Aur, T. Egami, A.E. Berkowitz and J.L. Walter. Physical Review B, 26, 6355 (1982). [PDF UCSD only]
  7. "Crystallization of Amorphous Fe75Si15B10 Ribbon and Powder", J.L. Walter, A.E. Berkowitz and E.F. Koch. Materials Science and Engineering, 60, 31 (1983). [PDF UCSD only]
  8. "Ferrofluids Prepared by Spark Erosion", A.E. Berkowitz and J.L. Walter. Journal of Magnetism and Magnetic Materials, 39, 75 (1983). [PDF UCSD only]
  9. "Polarized Neutron Study of the Magnetization Density Distribution within a CoFe2O4 Colloidal Particle", A.C. Nunes, C.F. Majkrzak and A.E. Berkowitz. Journal of Magnetism and Magnetic Materials, 39, 59 (1983). [PDF UCSD only]
  10. "Magnets (Permanent) and Magnetostatics", A.E. Berkowitz, in Concise Encyclopedia of Solid State Physics, ed. by R.G. Lerner and G.L. Trigg. Addison-Wesley Publishing Co., Reading, MA (1983).
  11. "Structures and Properties of Powders of Fe75Si15B10 Produced by Gas-Water Atomization", A.E. Berkowitz, J.C. Grande, S.A. Miller, R.J. Murphy and J.L. Walter. Materials Science and Engineering, 62, 217 (1984). [PDF UCSD only]
  12. "Properties of Mn-Al-C Magnets Prepared by Spark Erosion and Other Rapid Solidification Techniques", A.E. Berkowitz, J.D. Livingston and J.L. Walter. Journal of Applied Physics, 55, 2106 (1984). [PDF UCSD only]
  13. "Effect of Cooling Rate on the Atomic and Crystal Structure of Rapidly Cooled Fe75Si15B10", J.L. Walter and A.E. Berkowitz. Materials Science and Engineering, 67, 169 (1984). [PDF UCSD only]
  14. "The Effects of Additions on the Magnetic Properties and Atomic Structure of Amorphous Fe82-xMxB18 Alloys", J.L. Walter and A.E. Berkowitz, in Rapidly Quenched Metals, ed. by S. Steeb and E. Warlimont. Proceedings of 5th Conference on Rapid Solidification, Wurzberg, 1984. Elsevier Science Publishers B.V., 1303 (1985).
  15. "Ion-Beam-Enhanced Adhesion of Au Films on Si and SiO2", A.E. Berkowitz, R.E. Benenson, R.L. Fleischer, L. Wielunski and W.A. Lanford. Nuclear Instruments and Methods B, 7/8, 877 (1985). [PDFUCSD only]
  16. "Metastable Phases in Amorphous Metals with Emphasis on Fe3B", J.L. Walter and A.E. Berkowitz. Journal of Materials Science, 20, 1471 (1985). [PDF UCSD only]
  17. "Microstructure, Relaxation and Print-Through in ?-Fe2O3 Particles", A.E. Berkowitz, R.P. Goehner, E.L. Hall and P.J. Flanders. Journal of Applied Physics, 57, 3928 (1985). [PDF UCSD only]
  18. "Some Materials Considerations in Particulate Media", A.E. Berkowitz. IEEE Transactions on Magnetism, MAG-22, 466 (1986). [PDF UCSD only]
  19. "Microstructural Defects in ?-Fe2O3 Particles", E.L. Hall and A.E. Berkowitz. Journal of Materials Research, 1, 836 (1986). [PDF UCSD only]
  20. "Some Effects of Quench Rate on the Properties of Microstructures of Amorphous and Crystalline Particles Produced by Spark Erosion", J.L. Walter and A.E. Berkowitz. Proceedings of Materials Research Society Symposium, 80, 179 (1987).
  21. "Microstructure of ? Fe2O3 Particles: A Response to Andress, et. al.", A.E. Berkowitz, E.L. Hall and P.J. Flanders. IEEE Transactions on Magnetism, MAG-23, 3816 (1987). [PDF UCSD only]
  22. "Spark Erosion: A Method for Producing Rapidly Quenched Fine Powders", A.E. Berkowitz and J.L. Walter. Journal of Materials Research, 2, 277 (1987). [PDF UCSD only]
  23. "High-Resolution Transmission Electron Microscopy and X-ray Study of Colloidal Cobalt Ferrite Particles", A.C. Nunes, E.L. Hall and A.E. Berkowitz. Journal of Applied Physics, 63, 5181 (1988). [PDF UCSD only]
  24. "Toward a Model for Co-Surface-Treated Fe-Oxides", A. E. Berkowitz, F. T. Parker, E.L. Hall, G. Podolsky. IEEE Transactions on Magnetics, MAG-24, 2871 (1988). [PDF UCSD only]
  25. "Determination of Anisotropy Fields in Particulate Recording Media by Mössbauer Spectroscopy", F. T. Parker and A. E. Berkowitz. IEEE Transactions on Magnetics, MAG 25, 3647 (1989). [PDF UCSD only]
  26. "High Density Magnetic Recording Media for the Future", A. E. Berkowitz and R. M. White. Materials Science and Engineering, B3, 413 (1989). [PDF UCSD only]
  27. "Reversal Mechanisms and the Temperature Dependence of ?R/?S, HC and HK in Particle Assemblies", A. E. Berkowitz, F. T. Parker, and S. B. Slade. Journal of Applied Physics, 67, 9, 5155 (1990). [PDFUCSD only]
  28. "Anisotropy Field Distributions in Magnetics Recording Particles", F. T. Parker and A. E. Berkowitz. Journal of Applied Physics, 67, 5158 (1990). [PDF UCSD only]
  29. "Magnetic and Structural Properties of Granular Iron-Silicon Dioxide Thin Films", M. J. Carey, F. T. Parker, and A. E. Berkowitz. Materials Research Society Symposium Proceedings, 195, 445 (1990).

1991 - 1995

  1. "HC Enchancement in Partially Reduced ? Fe2O3 via Surface Treatment with Sodium Polyphosphate (revisited)", F. E. Spada, A. E. Berkowitz, and N. T. Prokey. Journal of Applied Physics, 69, 4475 (1991). [PDF UCSD only]
  2. "Preparation and Properties of Non-Interacting Spherical Magnetic Particles", S. B. Slade, A. E. Berkowitz and F. T. Parker, Journal of Applied Physics, 69, 5127 (1991). [PDF UCSD only]
  3. "Some Topics in Fine Particle Magnetism", A. E. Berkowitz, Proceedings of the NATO Advanced Study Institute on The Science and Technology of Nanostructured Materials, Crete, 533 (1991).
  4. "Preparation and Structural Characterization of Sputtered CoO, NiO and Ni0.5Co0.5O Thin Epitaxial Films", M. J. Carey, F. E. Spada, A. E. Berkowitz, W. Cao, and G. Thomas, Journal of Materials Research, 6, 2680 (1991). [PDF UCSD only]
  5. "Exchange Anisotropy in Coupled Films of Ni81Fe19 with NiO and CoxNi1-xO", M. J. Carey and A. E. Berkowitz, Applied Physics Letters., 60, 3060, (1992). [PDF UCSD only]
  6. "Characterization of Epitaxial Sputtered NixCo1-xO Thin Films on ? Al2O3 Using Transmission Electron Microscopy", W. Cao, G. Thomas, M. J. Carey and A. E. Berkowitz, Scripta Metallurgica et Materialia, 25, 2633 (1991). [PDF UCSD only]
  7. "Giant Magnetoresistance in Heterogeneous Cu-Co Alloys", A. E. Berkowitz, J. Mitchell, M. Carey, P. Young, S. Zhang, F. Spada, F. Parker, A. Hutten and G. Thomas, Physical Review Letters, 68, 3745, (1992). [PDF UCSD only]
  8. "Ultra-High Sensitivity B-H Looper/AC Susceptometer", S. B. Slade, and A. E. Berkowitz, IEEE Transactions on Magnetics, 28, 3132, 1992. [PDF UCSD only]
  9. "Field Response of Surface Spins on Co-Adsorbed ? Fe2O3", F. T. Parker and A. E. Berkowitz. Physical Review B , 44, 7437 (1991). [PDF UCSD only]
  10. "Giant Magnetoresistance in Heterogeneous Ag-Co Alloy Films", M. Carey, A. Young, A. Starr, D. Rao, and A. Berkowitz, Applied Physics Letters, 61, 2935 (1992). [PDF UCSD only]
  11. "Fine Particles in Magnetic Recording Media", A. Berkowitz, F. Parker, F. Spada, and D. Margulies, Magnetic Properties of Fine Particles, Proceedings of the International Workshop on Studies of Magnetic Properties of Fine Particles and their Relevance to Materials Science in Amsterdam, Netherlands, 309, 1992.
  12. "Spatially Modulated Antiferromagnetic Order in CoO/NiO Superlattices", J. A. Borchers, M. J. Carey, R. W. Erwin, C. F. Majkrzak, and A. E. Berkowitz. Physical Review Letters, 70, 1878 (1993). [PDF UCSD only]
  13. "Giant Magnetoresistance In Heterogeneous Cu-Co and Ag-Co Alloy Films", A. Berkowitz, J. Mitchell, M. Carey, A. P. Young, D. Rao, A. Starr, S. Zhang, F. E. Spada, F. T. Parker, A. Hutten, and G. Thomas. J. Appl. Phys. 73, 5320 (1993). [PDF UCSD only]
  14. "CoO-NiO Superlattices: Interlayer Interactions and Exchange Anisotropy with Ni81Fe19", M. J. Carey and A. E. Berkowitz. J. Appl. Phys. 73 6892(1993). [PDF UCSD only]
  15. "Propogation of Antiferromagnetic Order Across Paramagnetic Layers in CoO/NiO Superlattices", J. A. Borchers, M. J. Carey, A. E. Berkowitz, R. W. Erwin and C. F. Majkrzak, J. Appl. Phys. 73, 6898 (1993). [PDF UCSD only]
  16. "Studies of Anisotropy Mechanisms in Polyphosphate-treated Magnetic Iron Oxide Particles", F. E. Spada, F. T. Parker, C. Y. Nakakura, and A. E. Berkowitz, Journal of Magnetism and Magnetic Materials, 120, 129 (1993). [PDF UCSD only]
  17. "Spin Canting, Surface Magnetization, and finite-size Effects in ?-Fe2O3 Particles", F. T. Parker, M. W. Foster, D. T. Margulies, and A. E. Berkowitz, Phys. Rev. B, 47, 7885 (1993). [PDF UCSD only]
  18. "Polarized Neutron Reflection Study of the Unidirectional Magnetic Anisotropy of Permalloy on Ni0.5Co0.5O", G. P. Felcher, Y. Y. Huang, M. Carey and A. Berkowitz, Journal of Magnetism and Magnetic Materials, 120, 129 (1993). [PDF UCSD only]
  19. "Quantitative Characterization of Epitaxial Superlattices by X-ray Diffraction and High Resolution Electron Microscopy", E. E. Fullerton, W. Cao, G. Thomas, I. K. Schuller, M. J. Carey and A. E. Berkowitz, Appl. Phys. Lett. 63, 482, (1993). [PDF UCSD only]
  20. "HK Distributions and HC Calculations for Magnetic Recording Particles", F. T. Parker, A. E. Berkowitz, and S. B. Slade, J. Appl. Phys., 75:3, 1681, (1994). [PDF UCSD only]
  21. "Strong Interlayer Coupling in CoO-NiO Antiferromagnetic Superlattices", M. J. Carey, A. E. Berkowitz, J. A. Borchers, and R. W. Erwin, Physical Review B, 47, 9952, (1993). [PDF UCSD only]
  22. "Magnetism of Surface-Treated Particles", A. E. Berkowitz, F. E. Spada, and F. T. Parker, Nanophase Materials, G.C. Hadjipanayis and R. W. Siegel (eds). Kluwer Academic Publishers, 587 (1994).
  23. "Spark Erosion for Production of Nanocrystalline Materials", R. H. Kodama, A. E. Nash, F. E. Spada, and A. E. Berkowitz, Nanophase Materials, G. C. Hadjipanayis and R.W. Siegel (eds)., Kluwer Academic Publishers, 101, (1994).
  24. "Giant Magnetoresistance in Heterogeneous Alloy Films", A. E. Berkowitz, J. R. Mitchell, R. S. Beach, D. Rao, F. T. Parker, and F. E. Spada, IEEE Transactions on Magnetics, 30, 353, (1994). [PDF UCSD only]
  25. "HC Enchancement of Co-Adsorbed ?-Fe2O3 Particles via Surface Treatment With Sodium Polyphosphate", F. E. Spada, F. T. Parker, A. E. Berkowitz, and T. J. Cox, J. Appl. Phys., 75, 5562 (1994). [PDFUCSD only]
  26. "Low Temperature Magnetic Relaxation of Organic Coated NiFe2O4 Particles", R. H. Kodama, C. L. Seaman, A. E. Berkowitz, and M. B. Maple, J. Appl. Phys., 75, 5639 (1994). [PDF UCSD only]
  27. "Relaxation Measurements and Particle Size Determination in Co-Ag Heterogeneous Alloy Films", S. B. Slade, F. T. Parker, and A. E. Berkowitz, J. Appl. Phys. 75, 6613 (1994). [PDF UCSD only]
  28. "Magnetic Anomalies In Single Crystal Fe3O4 Thin Films", D. T. Margulies, F. T. Parker, and A. E. Berkowitz, J. Appl. Phys., 75, 6097 (1994). [PDF UCSD only]
  29. "Dependence of Giant Magnetoresistance on Film Thickness in Heterogeneous Co-Ag Alloys", J. R. Mitchell and A. E. Berkowitz, J. Appl. Phys., 75, 6912 (1994). [PDF UCSD only]
  30. "Fine Particle Synthesis by Spark Erosion", A. Berkowitz, R. Kodama, S. Slade and F. Spada, Nanomagnetism, A. Hernando, (ed), Kluwer Academic Publishers p. 87, (1993).
  31. "Giant Magnetic Field Dependent Impedance of Amorphous FeCoSiB Wire", R. S. Beach and A. E. Berkowitz, Appl. Phys. Lett., 64, 3652 (1994). [PDF UCSD only]
  32. "Anisotropy in Epitaxial Fe3O4 and NiFe2O4 Thin Films", D. T. Margulies, F. T. Parker, F. E. Spada and A. E. Berkowitz, Mat. Res. Soc. Symp.Proc., 341, 53 (1994).
  33. "Sensitive Field and Frequency Dependent Impedance Spectra of Amorphous FeCoSiB Wire and Ribbon", R. S. Beach and A. E. Berkowitz, J. Appl. Phys., 76, 6209 (1994). [PDF UCSD only]
  34. "Spark Erosion - A Fine Particle Technology", A. Berkowitz, R. Chau, R. H. Kodama, M. B. Maple, M. A. Meyers, and H. Wan. Proc. Joint NSF-NIST Conf. on Ultrafine Particle Engineering , May, 1994.
  35. "Microstructure of Sputtered Epitaxial Ni0.80Fe0.20/NixCo1-xO Exchange Coupled Bilayers on ?-Al2O3 (0001)", W. Cao, G. Thomas, M. J. Carey, and A.E. Berkowitz, J. Electron. Mater., 23 (1994). [abstract only available]
  36. "Determination of the Energy Barrier Distribution and Prefactor for Switching in a Heterogeneous Magnetic System", S. B. Slade, L. Gunther, F. T. Parker, and Ami E. Berkowitz, J. Magn. Magn. Mater., 140-144, 661(1995). [PDF UCSD only]
  37. "Synthesis of Nanocrystalline Titanium Carbide by Spark Erosion", M. S. Hsu, M. A. Meyers, and A. Berkowitz, Scripta Metall. et Mater, 32, 805 (1995). [PDF UCSD only]
  38. "Polarized Neutron Study of the Magnetization Density Distribution within a CoFe2O4 Colloidal Particle II", D. Lin, A. C. Nunes, C. F. Majkrzak, and A. E. Berkowitz, J. Magn. Magn. Mater., 145, 343 (1995). [PDF UCSD only]
  39. "Spin-Glass Behavior of Spinel Iron Oxide Particles On Iron Metal Particle Recording Media", F. T. Parker. F. E. Spada, T. J. Cox, and A. E. Berkowitz, J. Appl. Phys., 77, 5853 (1995). [PDF UCSD only]
  40. "Magnetoresistance Values Exceding 21% in Symmetric Spin Valves", W. F. Egelhoff, T. Ha, D. K. Mishra, J. Nir, C. J. Powell, M. D. Stiles, C. -L. Lin, M. J. Sivertsen, J. H. Judy, K. Takana, and A. E. Berkowitz, J. Appl. Phys., 78, 273 (1995). [PDF UCSD only]
  41. "Structure and Magnetic Properties of Nd-Fe-B Fine Particles Produced by Spark Erosion", H. Wan and A. E. Berkowitz, Scripta Metall et Mater., 32, 1827 (1995). [PDF UCSD only]

1996 - 2000

  1. "Magneto-Impedance Effect in NiFe Plated Wire", R. S. Beach, N. Smith, C. L. Platt, F. Jeffers, and A. E. Berkowitz., Appl. Phys. Lett., 68, 2753 (1996). [PDF UCSD only]
  2. "Unusual Magnetic Behavior in Nd2Fe14B-Fe Compacts", H. Wan, F. T. Parker, F. Putris, and A. E. Berkowitz, J. Appl. Phys., 79, 5504 (1996). [PDF UCSD only]
  3. " Anomalous Moment and Anisotropy Behavior in Fe3O4 Films", D. Margulies, F.T. Parker, F. E. Spada, R. Sinclair, R. S. Goldman, and A. E. Berkowitz. Phys. Rev. B. 53, 9175 (1996). [PDF UCSD only]
  4. "Microstructure of Sputtered Epitaxial Ni0.80Fe0.20/NixCo1-xO Exchange Coupled Bilayers on ?-Al2O3 (0001)", W. Cao, G. Thomas, M. J. Carey, and A.E. Berkowitz, J. Electron. Mater., 23 (1994). [abstract only available]
  5. "Surface Spin Disorder in NiFe2O4 Nanoparticles", R. H. Kodama, A. E. Berkowitz, E. J. McNiff, Jr, and S. Foner. Phys. Rev. Lett., 77, 394 (1996). [PDF UCSD only]
  6. "The Trade-off Between Large Magnetoresistance and Small Coercivity in Symmetric Spin Valves", W. F. Egelhoff, Jr., P. J. Chen, C. J. Powell, M. D. Stiles, R. D. McMichael, C. -L. Lin, J. M. Sivertsen, J. H. Judy, K. Takano, and A. E. Berkowitz, J. Appl. Phys., 79, 8603 (1996). [PDF UCSD only]
  7. "Optimizing the Giant Magnetoresistance of Symmetric and Bottom Spin Valves", W. F. Egelhoff, Jr., P. J. Chen. C. J. Powell, M. D. Stiles, R. D. McMichael, C. -L. Lin, J. M. Sivertsen, J. H. Judy, K. Takano, A. E. Berkowitz, T. C. Anthony, and J. A. Brug., J. Appl. Phys., 79, 5277 (1996). [PDF UCSD only]
  8. "Nanostructured Materials for Magnetic Recording", Ami Berkowitz. in Nanomaterials: Synthesis, Properties and Uses, ed. A.S. Edelstein and R. C. Cammarata (Institute of Physics Publishing, 1996), Ch. 26
  9. "Spin Dependent Tunneling in HfO2 Tunnel Junctions", C. L. Platt, B. Dieny, and A. E. Berkowitz, Appl. Phys. Lett., 69, 2291(1996). [PDFUCSD only]
  10. "Thermodynamic Measurements of Magnetic Ordering in Antiferromagnetic Superlattices", E. N. Abarra, K. Takano, F. Hellman, and A. E. Berkowitz, Phys. Rev. Lett., 77, 3451 (1996). [PDF UCSD only]
  11. "Combination High-sensitivity Alternating Current Susceptometer and High Frequency B-H Looper", S. B. Slade, G. Kassabian, and A. E. Berkowitz, Rev. Sci. Instr., 67, 2871 (1996). [PDF UCSD only]
  12. "Mossbauer Effect Study of Metal Particle Tape Stability", F. T. Parker, F. E. Spada, T. J. Cox, and A. E. Berkowitz, J. Magn. Magn. Mater., 162,122 (1996). [PDF UCSD only]
  13. "Growth of GMR Spin Valves using Pb and Au as Surfactants", W, F. Egelhoff, Jr., P. J. Chen, C. J. Powell, M. D. Stiles, R. D. McMichael, C.-L. Lin, J. M. Sivertsen, J. H. Judy, K. Takano, A. E. Berkowitz, J. Appl. Phys. 80, 5183 (1996). [PDF UCSD only]
  14. "Surface Spin Disorder in Ferrite Nanoparticles", R. H. Kodama, A. E. Berkowitz, E. J. McNiff, Jr. and S. Foner, in Synthesis and Properties of Mechanically Alloyed and Nanocrystalline Materials, eds. D. Fiorani and M. Magini (Materials Science Forum, vols.235-238 [1997], Trans Tech publications, Switzerland). p. 643.
  15. "Antiphase Domain Boundaries in Thin Films of Magnetite", M. L. Rudee, D. T. Margulies, and A. E. Berkowitz, Microsc. Microanal., 3, 126 (1997. [PDF UCSD only]
  16. "Magnetic Anomalies in NiO Particles", S. H. Makhlouf, F. T. Parker, F. E. Spada, and A. E. Berkowitz, J. Appl. Phys., 81, 5561 (1997). [PDFUCSD only]
  17. "Spin-Polarized Tunneling in Discontinuous CoFe/HfO2 Multilayers", S. Sankar, B. Dieny, and A. Berkowitz, J. Appl. Phys., 81, 5512 (1997). [PDF UCSD only]
  18. "Spin Polarized Tunneling in Reactively Sputtered Tunnel Junctions", C. L.Platt, B.Dieny, and A. E. Berkowitz, J. Appl. Phys., 81, 5523 (1997). [PDF UCSD only]
  19. "Nuclear Magnetic Resonance Investigations of Co Nanoclusters in a SiO2 Thin Film Matrix", T. Thomson, P. C. Reidl, S. Sankar, and A. E. Berkowitz, J. Appl. Phys., 81, 5549 (1997). [PDF UCSD only]
  20. "Surface Spin Disorder in Ferrite Nanoparticles", R. H. Kodama, A. E. Berkowitz, E. J. McNiff, Jr., and S. Foner, J. Appl. Phys., 81, 5552 (1997). [PDF UCSD only]
  21. "Magnetic Hysteresis Anomalies in Ferritin", S. H. Makhlouf, F. T. Parker, and A. E. Berkowitz, Phys. Rev. (Rapid Communications), B 55, R14 717 (1997). [PDF UCSD only]
  22. "Finite Size Effects in Antiferromagnetic NiO Nanoparticles", R. H. Kodama, S.A. Makhlouf, and A. E. Berkowitz, Phys. Rev. Lett., 79, 1393 (1997). [PDF UCSD only]
  23. "Anomalous Hysteresis Properties in Ferrimagnetic and Antiferromagnetic Nanoparticles", A. E. Berkowitz, R. H. Kodama, S. A. Makhlouf, F. T. Parker, F. E. Spada, E. J. McNiff, and S. Foner, "Magnetic Hysteresis in Novel Materials," ed. G. C. Hadjipanayis (Kluwer Academic Publishers, 1997). p. 293.
  24. "Specular Electron Scattering in GMR Spin Valves," W. F. Egelhoff, Jr., P. J. Chen, C. J Powell, M. D. Stiles, R. D. McMichael, D. H. Han, J. H. Judy, K, Takano, A. E. Berkowitz, and J. M. Daughton, IEEE Trans. Magn., 33, 3580 (1997). [PDF UCSD only]
  25. "The Origin of the Anomalous Magnetic Behavior in Single Crystal Fe3O4 Films", D.T. Margulies, F. T. Parker, M. L. Rudee, F. E. Spada, J. N. Chapman, P. E. Aitchison, and A. E. Berkowitz, Phys. Rev. Lett., 79, 5162 (1997). [PDF UCSD only]
  26. "Interfacial Uncompensated Antiferromagnetic Spins: Role in Uniaxial Anisotropy in Polycrystalline Ni81Fe19/CoO Bilayers", Kentaro Takano, R. H. Kodama, A. E. Berkowitz, W. Cao, and G. Thomas, Phys. Rev. Lett., 79, 1130(1997). [PDF UCSD only]
  27. "Spin-dependent tunneling in discontinuous metal/insulator multilayers", B. Dieny, S. Sankar, M. R. McCartney, D. J. Smith, P. Bayle-Guillemaud, and A. E. Berkowitz, J. Magn. Magn. Mater., 185, 283 (1998). [PDF UCSD only]
  28. " Magnetoresistance in Magnetite", J. M. D. Coey, A. E. Berkowitz, Ll. Balcells, F. F. Putris, and F. T. Parker. Appl. Phys. Lett., 72, 734 (1998). [PDF UCSD only]
  29. "Magnetoresistance of Chromium Dioxide Powder", J. M. D. Coey, A. E. Berkowitz, Ll. Balcells, and F. F. Putris. Phys. Rev. Lett., 80, 3815 (1998). [PDF UCSD only]
  30. "Structural Characterization of Thin Film Tunnel Junctions", David J. Smith, M. R. McCartney, C. L. Platt, and A. E. Berkowitz, J. Appl. Phys., 83, 5154 (1998). [PDF UCSD only]
  31. "Spin-Flip Tendencies In Exchange-Biased Co/CoO Thin Films", J. Borchers, Y. Ijiri, S-H. Lee, C. J. Majkrzak, G. P. Felcher, K. Takano, R. Kodama, and A. E. Berkowitz. J. Appl. Phys., 83, 7219 (1998). [PDF UCSD only]
  32. "Role of Interfacial Uncompensated Antiferromagnetic Spins in Unidirectional Anisotropy in Polycrystalline Ni81Fe19/CoO Bilayers", K. Takano, R. H. Kodama, and A. E. Berkowitz. J. Appl. Phys., 83, 6888 (1998). [PDF UCSD only]
  33. "Spin-Dependent Tunneling in Discontinuous Co-SiO2 Magnetic Tunnel Junctions", Sandra Sankar, A. E. Berkowitz, and David J. Smith. Appl. Phys. Lett., 73, 535 (1998). [PDF UCSD only]
  34. "NMR Studies of Sputtered CoFe Alloy Thin Films", T. Thomson, P. C. Riedl, C. L. Platt, and A. E. Berkowitz. IEEE Trans. Magn., 34, 1045 (1998). [PDF UCSD only]
  35. "Anomalous Behavior in Spin Dependent Tunnel Junctions", C. L. Platt, B. Dieny, A. Berkowitz. Mat.. Res. Soc. Symp. Proc., Vol. 475 (1997).
  36. "Optimizing GMR Spin Valves: The Outlook for Improved Properties", W. F. Egelhoff, Jr., P. J. Chen, C. J Powell, D. Parks, R. D. McMichael, D. H. Han, J. H. Judy, D. Martien, A. E. Berkowitz, and J. M. Daughton. Proc. Seventh Biennial IEEE Int. Nonvolatile Memory Technology Conf., Albuquerque, NM (1998).
  37. "Charge Storage in Co Nanoclusters Embedded in SiO2 by Scanning Force Microscopy", D. M. Schaadt, E. T. Yu, S. Sankar, and A. E. Berkowitz. Appl. Phys. Lett., 74, 472 (1999). [PDF UCSD only]
  38. "Atomic-Scale Magnetic Modeling of Oxide Nanoparticles", R.H. Kodama and A. E. Berkowitz. Phys. Rev. B, 59, 6321 (1999). [PDFUCSD only]
  39. "Increasing the Exchange-Bias Field of NiO0.05CoO0.5 Films by Microstructural Control", Dinesh Martien, Kentaro Takano, A. E. Berkowitz, and David J. Smith, Appl. Phys. Lett., 74, 1314 (1999). [PDF UCSD only]
  40. "Superconducting Tunneling as a Probe of Sputtered Oxide Barriers", C. L. Platt, A. S. Katz, R. C. Dynes, and A. E. Berkowitz, Appl. Phys Lett., 75, 127 (1999). [PDF UCSD only]
  41. "Exchange-biasing Asymmetric Spin Valves Using a Pulsed Current", S. Sankar, R.S. Beach, and A. E. Berkowitz, Appl. Phys. Lett., 75, 250 (1999). [PDF UCSD only]
  42. "Anomalous Properties of Magnetic Nanoparticles", A. E. Berkowitz, R. H.Kodama, Salah A. Makhlouf, F. T. Parker, F. E Spada, E. J. McNiff, Jr., and S. Foner, J. Magn. Magn. Mater., 196-197, 591 (1999). [PDF UCSD only]
  43. "A Monolithic Field-effect-transistor-amplified Magnetic Field Sensor", D. M. Schaadt, E. T. Yu, S. Sankar, and A. E. Berkowitz. Appl. Phys. Lett.,75, 731(1999). [PDF UCSD only]
  44. "Specular Electron Scattering in Metallic Thin Films", W. F. Egelhoff, Jr. P. J. Chen, C. J. Powell, D. Parks, G. Serpa, R. D. McMichael, D. Martien and A. E. Berkowitz. J. Vac. Sci. and Tech. B, 17, 1702 (1999). [PDF UCSD only]
  45. "Exchange Anisotropy – A Review", A. E. Berkowitz and Kentaro Takano, J. Magn. Magn. Mat., 200, 552 (1999). [PDF UCSD only]
  46. "Exchange Coupling Mechanisms at Ferromagnetic/CoO Interfaces", Kentaro Takano, F. T. Parker, and A. E. Berkowitz. Phys. Rev. B, 61, R866 (2000). [PDF UCSD only]
  47. "Superconducting and Spin-Dependent Tunneling Using Natural Oxide Barriers of CoFe Thin Films", C. L. Platt, A. S. Katz, E. P. Price, D. J. Smith, R. C. Dynes, and A. E. Berkowitz, Phys. Rev. B, 61, 68 (2000). [PDF UCSD only]
  48. "Magnetic Interlayer Coupling in Ferromagnetic/Insulator/Ferromagnetic Structures", C. L. Platt, M. R. McCartney, F. T. Parker, and A. E. Berkowitz, Phys. Rev. B, 61, 9633 (2000). [PDF UCSD only]
  49. "Correlation of Coercivity and Microstructure of Thin CoFe Films", C. L. Platt, A. E Berkowitz, David J. Smith, and S. Sankar, J. Appl. Phys., 88, 2058 (2000). [PDF UCSD only]
  50. "Magnetic Correlations in Non-percolated Co-SiO2 Granular Films", Sandra Sankar , A. E. Berkowitz, D. Dender, J. A. Borchers, R. W. Erwin, S. R. Kline, and D. J. Smith, J. Magn. Magn. Mater., 221, 1 (2000). [PDF UCSD only]
  51. "Spin-dependent transport of Co-SiO2 granular films approaching percolation", S. Sankar, A. E. Berkowitz, and David J. Smith. Phys. Rev. B, 62, 14273 (2000). [PDF UCSD only]

2001 - 2004

  1. "Thick Amorphous Ferromagnetic Coatings via Thermal Spraying of Spark-Eroded Powder", F. T. Parker, F. E. Spada, A. E. Berkowitz, K. S. Vecchio, E. J. Lavernia and R. Rodriguez, Mater. Lett., 48, 184 (2001). [PDF UCSD only]
  2. "Magnetically-soft, high moment, high-resistivity thin films using discontinuous metal/native-oxide multilayers", G. S. D. Beach, A. E. Berkowitz, F. T. Parker, and David J. Smith, Appl. Phys. Lett. 79, 224 (2001). [PDF UCSD only]
  3. "Reversal modes of exchange-spring magnets revealed by torque magnetometry", C. L. Platt, A. E. Berkowitz, S. David, Eric Fullerton, J.S. Jiang, and S.D. Bader, Appl. Phys. Lett. 79, 3992 (2001). [PDFUCSD only]
  4. "Do ballistic channels contribute to the magnetoresistance in magnetic tunnel junctions?", E. P. Price, David J. Smith R. C. Dynes, and A. E. Berkowitz, Appl. Phys. Lett. 80, 285 (2002). [PDF UCSD only]
  5. "Properties of the native oxide in metal/native oxide multilayers", G. S. D. Beach, A. E. Berkowitz, V. G. Harris, F. T. Parker, Bramadurai, and David J. Smith, J. Appl. Phys., 91, 7526 (2002). [PDF UCSD only]
  6. "Rotational hysteresis of exchange-spring magnets", J. S. Jiang, S. D. Bader, H. Kaper, G. K. Leaf, R. D. Shull, A. J. Shapiro, V. S. Gornakov, V. I. Nikitenko, C. L. Platt, A. E. Berkowitz, S. Davis, and E. E. Fullerton, J. Phys.: Appl. Phys. 35, 2339 (2002). [PDF UCSD only]
  7. "Exchange-spring permanent magnets produced by spark erosion", A. E. Berkowitz, M. F. Hansen, K. S. Vecchio, F. T. Parker, H. Harper, and F. E. Spada, Proc. 17th Int. Workshop on Rare Earth Magnets and Their Applications, (eds. G. C. Hadjipanayis and M. J. Bonder, Rinton Press, Princeton, New Jersey,2002}, p. 749.
  8. "Amorphous soft magnetic particles produced by spark erosion", A. E. Berkowitz, M. F. Hansen, F. T. Parker, K. S. Vecchio, F. E. Spada, E. J. Lavernia, and R. Rodriguez, J. Magn. Magn. Mater., 254-255, 1, (2003). [PDF UCSD only]
  9. "Finite size effects on the moment and ordering temperature in antiferromagnetic CoO layers", Y. J. Tang, David J. Smith, B. L. Zink, F. Hellman, and A. E. Berkowitz, Phys. Rev. B, 67, 054408 (2003). [PDF UCSD only]
  10. "Exchange-spring permanent magnet particles produced by spark erosion", M. F. Hansen, K.S. Vecchio, F. T. Parker, F. E. Spada, and A. E. Berkowitz, Appl. Phys. Lett., 82, 1574 (2003) [PDF UCSD only]
  11. "Energy absorption in Ni-Mn-Ga-polymer composites", J. Feuchtwanger, S. Michael, J. Juang, D. Bono, R. C. O’Handley, S. M. Allen, C. Jenkins J. Goldie, A. E. Berkowitz, J. Appl. Phys., 93, 8528 (2003). [PDF UCSD only]
  12. "Structure and phase transformation of ferromagnetic shape memory alloy Ni49Mn30Ga21 fine particles prepared by spark erosion", Y. T. Tang, David J. Smith, F. E. Spada, H. Harper, A. E. Berkowitz, IEEE Trans. Magn., 39, 3405 (2003). [PDF UCSD only]
  13. "High frequency characteristics of metal/native oxide multilayers", G. S. D. Beach, T. J. Silva, F. T. Parker, A. E. Berkowitz, IEEE Trans. Magn., 39, 3405 (2003). [PDF UCSD only]
  14. "New magnetic order in buried native oxide layers", G. S. D. Beach, F. T. Parker, David J. Smith, P. A. Crozier, and A. E. Berkowitz, Phys. Rev. Lett., 91, 267201 (2003). [PDF UCSD only]
  15. "Influence of Interface Alloying on the Magnetic Properties of Co/Pd Multilayers", J. Carrey, A. E. Berkowitz, W. F. Egelhoff, D. Smith, Appl. Phys. Lett., 83, 5259 (2003). [PDF UCSD only]
  16. "Spark-eroded particles: influence of processing parameters", J. Carrey, H. B. Radousky and A. E. Berkowitz, J. Appl. Phys., 95, 823 (2004). [PDF UCSD only]
  17. "Microstructural Characterization of Ni-Mn-Ga Ferromagnetic Shape Memory Powders", V. Solomon, David J. Smith, YunJun Tang and Ami .E. Berkowitz, J. Appl. Phys., 95, 6954 (2004). [PDF UCSD only]
  18. "Hollow Metallic Microspheres Produced by Spark Erosion", A. E. Berkowitz, H. Harper, David J. Smith, Hao Hu, Qiang Jiang, Virgil C. Solomon, and H. B. Radousky, Appl. Phys. Lett., 85, 940 (2004). [PDF UCSD only]
  19. "Co50Fe50 Fine Particles for Power Frequency Applications," Y. J. Tang, F. T. Parker, H. Harper, A. E. Berkowitz,, Q. Jiang, David. J Smith, M. Brand, F. Wang, IEEE Trans. Magn., 40, 2002 (2004). [PDFUCSD only]
  20. "Critical Sizes for Ferromagnetic Spherical Hollow Particles", D. Goll, A. E. Berkowitz, and H. N. Bertram, Phys. Rev. B 70, 184432 (2004). [PDF UCSD only]

2005 - 2010

  1. "On the Perpendicular Anisotropy of Co/Pd Multilayers", J. I. Hong, S. Sankar, A. E. Berkowitz, and W. F. Egelhoff, J. Magn. Magn. Mater. 285, 359 (2005). [PDF UCSD only]
  2. "Microstructure, exchange coupling and magnetization reversal in nanocrystalline Nd2(FeCo)14B/?-Fe particles produced by spark erosion", Y. J. Tang, F. T. Parker, H. Harper, A. E. Berkowitz, K. Vecchio, A. Rohatgi, and Bao-Min Ma, Appl. Phys. Lett., 86, 122507 (2005). [ PDF UCSD only]
  3. "Magnetocaloric effect in NiMnGa particles produced by spark erosion", Y. J. Tang, Virgil C. Solomon, D. J. Smith, H.Harper, and A. E. Berkowitz, J. Appl. Phys., 97, 10M309 (2005). [PDF UCSD only]
  4. "Large energy absorption in Ni-Mn-Ga/polymer composites", Jorge Feuchtwanger, Marc L. Richard, Y. J. Tang, Y. I. Hong, Ami E. Berkowitz, Robert C. O'Handley, and Samuel M. Allen, J. Appl. Phys., 97, 10M319 (2005). [PDF UCSD only]
  5. "Surface-driven Effects On The Magnetic Behavior Of Oxide Nanoparticles", R. H. Kodama and A. E. Berkowitz, in Surface Effects in Magnetic Nanoparticles, ed. D. Fiorani (Kluwer Publishers, 2005).
  6. "CoxFe100-xMetal/Native-Oxide Multilayers: A New Direction in Soft Magnetic Thin Film Design, I. Quasistatic Properties and Dynamic Response;[PDF UCSD only] II. Microscopic Characteristics and Interactions", G. S. D Beach and A. E. Berkowitz, IEEE Trans. Magn., 41, 2043 (2005) [PDF UCSD only]
  7. "Establishing Exchange Bias Below TN with Polycrystalline Ni0.52Co0.48O–Co Bilayers", A. E. Berkowitz, M. F. Hansen, R. H. Kodama, Y. J. Tang, J. I. Hong, and David. J. Smith, Phys. Rev.B, 72, 134428 (2005). [PDF UCSD only]
  8. "Magnetic domain configurations in spark-eroded ferromagnetic shape memory Ni-Mn-Ga particles", Virgil C. Solomon, Martha McCartney, YunJun Tang, Ami E. Berkowitz, Robert C. O'Handley, and David J. Smith, Appl. Phys. Lett. 86, 192503 (2005). [PDF UCSD only]
  9. "Enhancing Exchange Bias with Diluted Antiferromagnets", Jung-Il Hong, Titus Leo, David J. Smith, and Ami E. Berkowitz, Phys. Rev Lett. 96, 117204 (2006). [PDF UCSD only]
  10. "Exchange Anisotropy", A. E. Berkowitz and R. H. Kodama, in Nanomagnetism 1; Multilayers, Ultrathin Films, and Textured Media, eds., J. A. C. Bland and D. L. Mills, pp. 115-152, (Elsevier, 2006).
  11. "Magnetic Ground States and the Role of Vortices in Ferromagnetic Hollow Nanospheres", D. Goll, S Macke, A. E. Berkowitz, and H. N. Bertram, Physica B, 372, 282 (2006). [PDF UCSD only]
  12. "Permeabiity of Fine Magnetic Particles: Measurements, Calibration, and Pitfalls", D. W. Lee, S. X. Wang, J.-I. Hong, and A. E. Berkowitz, IEEE Trans. Magn., 42, 3335 (2006). [PDF UCSD only]
  13. "One-Step Production of Optimized Fe-Ga Particles by Spark Erosion", J. I. Hong, V. C. Solomon, David J. Smith, F. T. Parker, E. M. Summers, and A. E. Berkowitz, Appl. Phys. Lett., 89, 142506 (2006). [PDF UCSD only]
  14. "Electron Microscopy Investigations of Spark-eroded Ni-Mn-Ga Ferromagnetic Particles", Virgil C. Solomon, Jung-Il Hong, YunJun Tang, Ami E. Berkowitz and David J. Smith, Scripta. Mat., 56, 593 (2007) [PDF UCSD only]
  15. "Evidence of Modified Magnetism At A Buried Permalloy/Co Interface at Room Temperature," S. Roy, C. Sanchez-Hanke, S. Park, M. R. Fitzsimmons, Y. J. Tang, J. I. Hong, David J. Smith, B. J. Taylor, X. Liu, M. B. Maple, A. E. Berkowitz, C.-C. Kao and S. K. Sinha, Phys. Rev. B, 75, 014442 (2007). [PDF UCSD only] [Erratum UCSD only]
  16. "Unusual Co Moment Reduction in the NiCoO/Co Exchange BiasSystem," S. Bruck , E.Goering, Y. J. Tang, G. Schutz, A. E. Berkowitz. J. Magn. Magn. Mat. 310, 2316 (2007). [PDF UCSD only]
  17. "Correlation of microstructure and magnetic properties for exchange-biased Co ferromagnets grown above and below the diluted antiferromagnet Co(Mg)O", Titus Leo, Jung-Il Hong, Ami E. Berkowitz, and David J. Smith, J. Appl. Phys., 102, 123904 (2007). [PDF UCSD only]
  18. "Antiferromagnetic MnO Nanoparticles with Ferrimagnetic Mn3O4 Shells: A Doubly-Inverted Core-Shell System", A.E. Berkowitz, G.F. Rodriguez, J. I. Hong, K. An, T. Hyeon, N. Agarwal, D. J. Smith, and E. E. Fullerton, Phys. Rev. B, 77, 0244403 (January 2008). [PDFUCSD only]
  19. “Monodispersed MnO nanoparticles with epitaxial Mn3O4 shells”, A.E. Berkowitz, G.F. Rodriguez, J.I. Hong, K. An, T. Hyeon, N. Agarwal, D.J. Smith, and E.E. Fullerton, J. Phys. D: Appl. Phys., 41, 134007-1-5 (July 2008). [PDF UCSD only]
  20. "Spherical particles with mixed amorphous/crystalline nanostructured cores and insulating oxide shells” J. I. Hong, F. T. Parker, V. C. Solomon, P. Madras, David J. Smith, A. E. Berkowitz, J. Mater. Res., 23, 1758 (2008). [PDF]
  21. “Pinned Co moments in a polycrystalline permalloy/CoO exchange-biased bilayer”, E. Blackburn, C. Sanchez-Hanke, S. Roy, D.J. Smith, J-I Hong, K.T. Chan, A.E. Berkowitz, and S.K. Sinha, Physical Review B (Condensed Matter and Materials Physics), 78, 18, pp. 180408 (4) (November 2008). [PDF UCSD only]
  22. “Refining the exchange anisotropy paradigm: Magnetic and microstructural heterogeneity at the permalloy-CoO interface”, A.E. Berkowitz, J-I. Hong, S.K. McCall, E. Shipton, K.T. Chan, T. Leo, and D.J. Smith, Physical Review B, 81, 13, pp. 134404-1-9, (April 2010). [PDF UCSD only]

2011 - 2015

  1. "Spark erosion: a high production rate method for producing Bi0.5 Sb1.5Te3 nanoparticles with enhanced thermoelectric performance”, P. K. Nguyen, K. H. Lee, S. I. Kim, K. A. Ahn, L. H. Chen, S. M. Lee, R. K. Chen, S. Jin, and A. E. Berkowitz, Nanotechnology 23, 415604 (2012). [PDF ucsd only]
  2. “Unexpected Magnetic Domain Behavior in LTP-MnBi," P.K. Nguyen, S. Jin, and A. E. Berkowitz, IEEE Transactions on Magnetics, Vol. 49, No. 3387, 2013. [PDF]
  3. “Nonswitchable magnetic moments in polycrystalline and (111)-epitaxial permalloy/CoO exchange-biased bilayers” S.-W. Chen, X. Lu, E. Blackburn, V. Lauter, H. Ambaye, K. T. Chan, E. E. Fullerton, A. E. Berkowitz, and S. K. Sinha, Physical Review B89, 094419 (2014). [PDF]
  4. “MnBi particles with high energy density made by spark erosion”, Phi-Khanh Nguyen, Sungho Jin, and Ami E. Berkowitz,Journal of Applied Physics 115, 17A756 (March 2014).[PDF]

  5. "Rare‐Earth‐Free Permanent Magnets for Electrical Vehicle Motors and Wind Turbine Generators: Hexagonal Symmetry Based Materials Systems Mn‐Bi and M‐type Hexaferrite." Hong, Yang-Ki, Timothy Haskew, Oleg Myryasov, Sungho Jin, and Ami Berkowitz. No. DOE-ALABAMA-0000189. 1. University of Alabama, Tuscaloosa, AL; 2. University of California, San Diego, CA; 3. Mississippi State University, Mississippi State, MS, June, 2014. [PDF]

Patents

  1. "Liquid Identification Using Magnetic Particles Having a Preselected Curie Temperature." Ami E. Berkowitz and William H. Meiklejohn. May 29, 1973. No. 3,736,500.
  2. "Non-Impact Curie Point Printer." Ami E. Berkowitz and William H. Meiklejohn. August 1974. No. 3,832,718.
  3. "Direct Current Bias Fields for Magnetic Printing." Ami E. Berkowitz and Joseph A. Lahut. March 23, 1976. No. 3,946,404.
  4. "Magnetic Brush for Use in Magnetic Printing." Ami E. Berkowitz. March 23, 1976. No. 3,945,343.
  5. "Recording Head Array with Passive Pole." Ami E. Berkowitz. January 4, 1977. No. 4,001,841.
  6. "Transverse Recording Head for Magnetic Printing." Ami E. Berkowitz, Joseph A. Lahut and Jish Min Wang. June 27, 1978. No. 4,097,871.
  7. "Printing Head and Brush Configuration for Magnetic Printer." Ami E. Berkowitz and Joseph A. Lahut. October 24, 1978. No. 4,122,456.
  8. "Apparatus and Methods for Fabrication of Magnetic Printing Belt." Ami E. Berkowitz, John O. Fielding and Joseph A. Lahut. October 24, 1978. No. 4,121,964.
  9. "Magnetic Belt with Conductive Coating." Ami E. Berkowitz and Joseph A. Lahut. December 11, 1979. No. 4,178,405.
  10. "Polymer Based Magnetic Tags." Ami E. Berkowitz and Fred F. Holub. April 15, 1980. No. 4,198,307.
  11. "High Resolution Magnetic Printing Head." Ami E. Berkowitz. May 4, 1982. No. 4,328,503.
  12. "Easily Assembled Transverse Magnetic Printing Head." Ami E. Berkowitz, Joseph A. Lahut and Jish Min Wang. January 25, 1983.No. 4,370,661.
  13. "Ferrofluid." Ami E. Berkowitz and J.L. Walter. April 26, 1983. No. 4,381,244.
  14. "Process for Producing a Ferrofluid." Ami E. Berkowitz and J.L. Walter. November 22, 1983. No. 4,416,751.
  15. "Method for Fabrication of Low Cost Finely Divided Silicon-Germanium and Consolidated Compacts Thereof." J.L. Walter and A.E. Berkowitz. July 26, 1988. No. 4,759,905.
  16. "Method for and Reaction for Sustaining High Energy Reactions", Robert E. Smith and Ami E. Berkowitz. Oct. 29, 1991. No. 5,061,354.
  17. "Giant Magnetoresistant Single Film Alloys". Ami Berkowitz. Oct. 31, 1995. No. 5,462,809.
  18. "Giant Magnetoresistance Single Film Alloys". Ami Berkowitz. Jan. 7, 1997. No. 5,591,532.
  19. "Giant Magnetoresistant single Film Alloys", Ami Berkowitz, Feb. 9, 1999. No. 5,868,910.

Prof. Berkowitz's group is developing new materials for read and write heads and for thin film and particulate media, with the objective of meeting the requirements of ultra-high density storage. Some recent achievements have been the introduction of stable antiferromagnetic oxides for MR head biassing, the development of heterogeneous alloys exhibiting Giant Magneto-Resistance, and the demonstration of Giant Magneto-Impedance in thin films.

There is a strong emphasis on utilizing the most advanced characterization techniques, in order to establish a rigorous basis for understanding and optimizing materials properties. Some current programs are: investigating surface treatment and composite structures for thin film storage media; developing new stable particulate media; examining the influence of diminishing size on the properties, and their stability in time, of the magnetic subunits in films and particles; defining the basic structural and physical parameters involved in the biassing of ferromagnetic films by antiferromagnetic materials; producing the optimum magneto-transport properties in granular and heterogeneous materials, as well as in spin polarized tunnel junctions.


Graduate Student(s)

Student Name: Naveen Pouse
Email: npouse@ucsd.edu


Undergraduate Student(s)

Student Name: Alexandre Bezerra


Visiting Undergraduate Student(s):

Student Name: Gustavo Meirelles Dos Santos


Alumni

Student Name: Phi Nguyen
Dissertation: Development of Thermoelectric and Permanent Magnet Nanoparticles for Clean Energy Applications [Abstract] [PDFUCSD only]
Degree: Ph.D.
Year: 2015

Student Name: Geoff Beach
Dissertation: Magnetic Properties Of Coxfe100-X¬ Metal/Native Oxide Multilayers [Abstract] [PDF UCSD only]
Degree: Ph.D.
Year: 2003

Student Name: Matthew Carey
Dissertation: Coxni1-Xo Thin Films and Coo-Nio Superlattices: Structure, Magnetic Properties And Exchange Anisotropy With Ni81fe19 [Abstract only]
Degree: Ph.D.
Year: 1993

Student Name: Chulmin (Edward) Choi *
Dissertation: Nano Fabrication Approaches for Patterned Magnetic Recording Media [Abstract] [PDF UCSD only]
Degree: Ph.D.
Year: 2010

Student Name: Richard Kodama
Dissertation: Finite Size and Interface Effects in Magnetic Oxide Nanoparticles and Films [Abstract] [PDF UCSD only]
Degree: Ph.D.
Year: 1997

Student Name: David Margulies
Dissertation: Origin of the Anomalous Magnetic Behavior in Single Crystal Fe304 Films and Cobalt Surface Treatment of Iron Oxide Thin Films [Abstract] [PDF UCSD only]
Degree: Ph.D.
Year: 1996

Student Name: Christopher Platt
Dissertation: Magnetic and Transport Properties of Spin Dependent Tunnel Junctions [Abstract] [PDF UCSD only]
Degree: Ph.D.
Year: 2000

Student Name: Edward P. Price
Dissertation: Characterization of Transport Processes in Magnetic Tunnel Junctions [Abstract] [PDF UCSD only]
Degree: Ph.D.
Year: 2001

Student Name: Sandrawattie Sankar
Dissertation: Correlation of Microstructural, Magnetic, And Transport Properties Of Composite Metal-Insular Films [Abstract] [PDF UCSD only]
Degree: Ph.D.
Year: 2000

Student Name: Steven Slade
Dissertation: Investigation of The Neel Model Of Thermal Activation In Heterogeneous Co-Ag Alloy Films Through The Use Of Dynamic Susceptibility Measurements [Abstract only]
Degree: Ph.D.
Year: 1994

Student Name: Kentaro Takano
Dissertation: Exchange Anisotropy in Thin Film Bilayers Of Nickel Cobalt Monoxide And Various Ferromagnetic Materials [Abstract] [PDF UCSD only]
Degree: Ph.D.
Year: 1998

*jointly supervised with Prof. Sungho Jin - MAE Dept.


Past Project Scientist(s)

Fred Parker


Past Visiting Scholar(s)

Luis Balcells I Argemi

Yunki Kim


Past Visiting Student(s)

Eugene Chudnovsky