Superconductivity and structural instability of (Hf, Zr)V₂and (Hf, Ta)V₂alloys at high pressure

Abstract

The superconducting transition temperature and the temperature of the structural instability in (Hf1-xZrx)V2(0<or=x<or=1) and (Hf1-xTax)V2(0<or=x<or=0.2) alloys have been determined as a function of hydrostatic pressure to 24 kbar. Tc either increases or remains essentially constant under pressure, depending on whether the alloy is HfV2 or ZrV2 rich. A correlation is found between the increase of Tc and the temperature T0 at which the structure becomes unstable.