Accession Number : ADA320603

Title :   Synthesis and Characterization of CuO Superconductors with Anomalous Transitions above 200 K.

Descriptive Note : Final rept. 1 Jun 93-31 Oct 96,

Corporate Author : WAYNE STATE UNIV DETROIT MI DEPT OF PHYSICS

Personal Author(s) : Wenger, Lowell E. ; Chen, J. T.

PDF Url : ADA320603

Report Date : 31 DEC 1996

Pagination or Media Count : 52

Abstract : This final report describes our continual superconductivity research on the materials and structural phases responsible for the above 200-K superconducting transitions, their synthesis conditions, and the study of the physical properties associated with these transitions. These transitions are characterized by resistive drops and flux-trapping hysteretic behavior in the magnetization measurements. Information on the magnetic properties of a reproducible flux-trapping phenomenon occurring at 336 K as well as on the synthesis conditions and structural features of multi-phase YBaCuO samples which exhibit this phenomenon are detailed. Also studies of the Josephson properties on YBaCuO single crystals are presented which indicate intrinsic Josephson junctions at the inter- and intra-unit-cell length scales. This latter result has a strong implication for atomic-plane 2-dimensional superconductivity in the cuprate superconductors. In addition, studies of the paramagnetic Meissner effect on Nb disks and cuprate samples indicate that the effect is not an intrinsic property, but dependent upon the sample geometry and the surface microstructure.

Descriptors :   *ANOMALIES, *SUPERCONDUCTORS, *TRANSITIONS, *COPPER OXIDES, *YTTRIUM COMPOUNDS, MEASUREMENT, MAGNETIC PROPERTIES, MICROSTRUCTURE, SYNTHESIS, PHYSICAL PROPERTIES, STRUCTURAL PROPERTIES, COMPOSITE MATERIALS, SINGLE CRYSTALS, PHASE, SURFACES, NIOBIUM, GEOMETRY, DISKS, MAGNETIZATION, ATOMIC PROPERTIES, BARIUM, JOSEPHSON JUNCTIONS, HYSTERESIS, SUPERCONDUCTIVITY, PARAMAGNETISM.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Electrical and Electronic Equipment
      Electricity and Magnetism
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE