SOME THERMAL AND ELECTRICAL PROPERTIES OF THE HIGH-Tc SUPERCONDUCTORS Y-Ba-Cu AND Bi-Sr-Ca-Cu OXIDES

Abstract
The heat capacity, Cp, has been measured in the range 0.4 to 20 K and the linear thermal expansivity, α, in the range 2 to 283 K of YBa 2 Cu 3 O 7. Below 4 K Cp exhibits a T-term (≈ 7.5 T mJ/mol.K ), but in general both Cp(T) and α(T) have magnitudes and T-dependences that are not very different from other ceramics. The electrical resistance of YBa 2 Cu 3 O 7 and Bi 2 Sr 1.7 CaCu 2 O 8 samples have been measured in the range 20 to 120 K and in magnetic fields of up to 7 T. In all cases the value of T c is highly sensitive to the applied magnetic field. The upper critical field, B c2 (0), is estimated to be 68.5 T for YBa 2 Cu 3 O 7 and 55 T for Bi 2 Sr 1.7 CaCu 2 O 8.

This publication has 0 references indexed in Scilit: