Solid state science: magnetic information storage; superconductivity
University of Vienna
Awards and Academic Honors
Appointed to faculty, Oregon Graduate Center
Appointed to faculty, Cornell University
Postdoctoral fellow, Brookhaven National Laboratory
Postdoctoral fellow, University of Pittsburgh
Our research interests lie in the area of solid state science. They are centered on the idea of creating and understanding certain electronic and structural conditions which lead to unusual solid state properties. Our experiments consist of synthesis, structural analysis, and the application of various solid state probes, such as low temperature magnetic susceptibility, conductivity, Mössbauer effect, thermal studies, and ESR.
We are especially interested in compounds of rare earth and transition metals and their oxides in bulk or thin film form. These materials are often magnetically ordered, especially at low temperatures. The crystalline electric field influences both the magnitude of magnetic moment and the force with which magnetic moments are held in a certain crystallographic direction. Quantum mechanical calculations are used in our laboratory to compare experiment with theory. Outstanding values of magnetic anisotropy establish a host of interesting properties from magnetic hardness to magnetostriction and magnetooptic activity. These properties are of interest for electronic devices or information storage in computers or video recorders. In fact, we pursue work on information storage materials within the newly established Center for Magnetic Recording Research on campus.
We are also engaged in work on the new ceramic superconductors, such as YBa2,Cu3O7. We study their O intercalation behavior or questions of electron localization versus metallic conductivity or superconductivity. New synthetic approaches may make it possible to raise their superconducting transition temperatures well above the present record of Tc = 130 K. We plan to study partial halogen insertion as well as high pressure and electrochemical preparations and single crystal growth of these spectacular materials.
Intermetallic compounds can also form metal hydrides. Here, hydrogen can behave in a more or less metallic manner, but it is, indeed, an unusual metal. Highly electronegative and much lighter than any other element, it is a fascinating probing ground for studying the way magnetic order evolves or for creating new superconductors. It was recently discovered that hydrogen is stored in intermetallic compounds with a density twice that of liquid hydrogen, and is available within seconds in this form. These materials may become important for an economy based on hydrogen, with the development of hydrogen-powered cars, planes, and utility applications. We also found that metal hydrides support catalytic reactions of interest, among others, for electrochemical cells.
Primary Research Area
- Indications for Enhanced Flux Pinning below Magnetic Ordering of Fe Clusters in YBa2(CuFe)3Oy. With M.G. Smith, Physica C 204, 130 (1992).
- Mössbauer Study of YBa2(Cu1Fex)3 Oy. With M.G. Smith and R.D. Taylor. Phys. Rev. B. 42, 4202 (1990).
- Thermodynamics of O Uptake in the YBa2Cu3Ox Superconductor. With M. Smith. Mat. Res. Bull. 22, 1709 (1987).
- Giant Intrinsic Magnetic Hardness--Monte Carlo Simulations on Randon Systems. With M. Fahnle. Phys. Rev. 27, 5586 (1983).
- Metal Hydride Catalysis. With J. Elton. J. Solid State Chem. 48, 128 (1983).
- Hydrides of Intermetallic Compounds. Appl. Phys. 24, 169 (1981).