Accession Number : ADA257724


Title :   EM Properties of High Tc Superconductors


Descriptive Note : Final technical rept. Jun 1990-Jun 1991


Corporate Author : NORTHEASTERN UNIV BOSTON MA


Personal Author(s) : Sridhar, S


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a257724.pdf


Report Date : Jun 1992


Pagination or Media Count : 12


Abstract : The aim of this contract was to study the factors influencing microwave properties o high TC superconductors, via fundamental measurements on high quality thin film and single crystal materials. Two principal lines of investigation were pursued: In single crystals of Y,Ba2CU307-6 (Tc=93K) ultrasensitive rf methods were used to stud the penetration depth A, lower critical fields Hc1 and vortex pinning forces. The penetration depth and surface resistance were found to obey temperature dependences i good agreement with BCS calculations. The anisotropy and temperature dependence of Hc1 were measured and also found to be in good agreement with BCS theory. The pinning forces were measured, and the results imply that in good quality single crystals, the pinning is due to core pinning by defects, and implies intrinsic critical currents 2xl0 to the 7 power A/CM2.


Descriptors :   *ANISOTROPY , *YTTRIUM COMPOUNDS , MEASUREMENT , TEMPERATURE , CORES , CONTRACTS , MATERIALS , RESISTANCE , SUPERCONDUCTORS , THEORY , THIN FILMS , FILMS , SINGLE CRYSTALS , MICROWAVES , CRYSTALS , DEPTH , CRITICAL TEMPERATURE , SURFACES , PENETRATION , BARIUM COMPOUNDS , AGREEMENTS , POWER , COPPER COMPOUNDS , QUALITY , OXIDES


Subject Categories : Crystallography
      Solid State Physics


Distribution Statement : APPROVED FOR PUBLIC RELEASE