Ph.D. University of Pennsylvania, 1953
Our research is principally concerned with magnetic materials in the form of thin films, multilayers, and fine particles. We prepare, characterize, and model the properties of these materials. Sample preparation involves sputtering, electron beam evaporation, laser ablation, and spark erosion. We use a wide variety of characterization techniques such as high resolution transmission electron microscopy; x-ray, electron, and neutron diffraction; Mssbauer spectroscopy; magnetometry; transport measurements; nuclear magnetic resonance; magnetic imaging; etc. Much of this research is carried on with collaborators world-wide.
Some current research topics are: finite size effects in magnetic materials, thermally activated magnetization reversal, macroscopic quantum tunneling, magnetic interactions at interfaces between ferromagnetic and antiferromagnetic materials, spin-dependent tunnel junctions, transport in discontinuous multilayers, and new magnetic film storage media.
Selected Publications
"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).
"Giant Magnetoresistance in Heterogeneous Cu-Co Alloys," A. E. Berkowitz, J. Mitchell, M. Carey, P. Young, S. Zhang, F. Spada, F. Parker, Physical Review Letters, 68, 25, 3745, (1992).
"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, 6611(1995).
"Magneto-Impedance Effect in NiFe Plated Wire", R. S. Beach, N. Smith, C. L.Platt, F. Jeffers, and A. E. Berkowitz. ,Applied Physics Letters., 68, 2753 (1996).
"Surface Spin Disorder in NiFe2O4 Nanoparticles", R. H. Kodama, A. E. Berkowitz, E. J. McNiff, Jr, and S. Foner,Physical Review Letters., 77, 394 (1996).
"Spin Dependent Tunneling in HfO2 Tunnel Junctions", C. L. Platt, B. Dieny, and A. E. Berkowit z, Applied Physics Letters, 69, 2291(1996).
"Thermodynamic Measurements of Magnetic Ordering in Antiferromagnetic Superlattices", E. N. Abarra, K. Takano, F. Hellman, and A. E. Berkowitz, Physical Review Letters, 77, 3451 (1996).