Comparative critical field study of superconducting ternary borides

• Published in: Journal of low temperature physics Vol. 68; no. 1-2; pp. 147 - 157
• Main Authors: LEE, W. H, APPL, S, SHELTON, R. N
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01-07-1987
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Occurrence, potential candidates; Physics; Superconductivity; Electrical conductivity; Lutetium Osmium Borides Mixed; Transition metal Compounds; Superconductivity; Critical field; Experimental study; Scandium Ruthenium Borides Mixed; Inorganic compound; Rhodium Thorium Borides Mixed; Rhodium Yttrium Borides Mixed; Lanthanide Compounds; Ruthenium Yttrium Borides Mixed; Superconducting transition
• ISSN: 0022-2291; 1573-7357
• DOI: 10.1007/BF00682626

The upper critical field (H sub(c2)) and electrical transport properties have been determined for ternary rare-earth transition-metal borides with a variety of crystal structures; namely, ScRu sub(4)B sub(4) (I4 sub(1)/acd), LuRh sub(4)B sub(4) (I4 sub(1)/acd), ThRh sub(4)B sub(4) (P4 sub(2)/nmc), LuOs sub(3)B sub(2) (P6/mmm), LuTuB sub(2) (Pnma), and YRuB sub(2) (Pnma). For the majority of the compounds the critical field measurements are analyzed in terms of the dirty limit (l sub(tr)/ xi sub(BCS)(0) much greater than 1) theory of Werthamer, Helfand, and Hohenberg (WHH). For the superconductor YRuB sub(2), which is in the clean limit, critical field data are analyzed in terms of the Ginzburg-Landau theory. From the experimental data for (dH sub(c2)/dT) sub(T+Tc), and residual resistivity rho sub(res), The authors also have determined the heat capacity coefficient gamma and BCS coherence length xi sub(BCS)(0). The Kappa values indicate that these compounds are all strong type II superconductors.