Magnetic and superconducting properties of A7B3 compounds (A=Th or La and B=Ni, Co, Fe or Pd, Rh, Ru)

P. PEDRAZZINI; G. SCHMERBER; M. GÓMEZ BERISSO; J.P. KAPPLER; J.G. SERENI

PHYSICA C - SUPERCONDUTIVITY

Elsevier Science

Año: 2000 vol. 336 p. 10 - 18

0921-4534

High-temperature magnetization, low temperature specific heat, and ac-susceptibility measurements on Th7X3 (X=Ni, Co, and Fe) and La7Z3 (Z=Pd, Rh, and Ru) superconductors are presented. The magnetic behaviour of the Th7X3 group has the characteristics of Pauli paramagnets. The La7Z3 group also shows Pauli paramagnetism for Z=Pd and Ru, and signs of spin fluctuations for La7Rh3. Specific heat (CP) measurements indicate a conventional BCS behaviour for La7Pd3 and La7Rh3, like that of the previously measured Th7X3 superconductors. In the case of La7Ru3, the reduced specific heat jump at the transition, the anomalous temperature dependence of CP under magnetic field and a large upper critical field slope are discussed.