Relation between the superconducting transition temperature and the axial ratio in RNi2b2C(R=Y,Ho,Er,Tm,Lu)under high pressure

Abstract

The effect of pressure on the lattice parameters of RNi2B2C (R = Y, Ho, Er, Tm, Lu) has been measured in order to investigate the relation of T-C to axial ratio c/a in the tetragonal lattice or the cohesive properties of these materials. The large anisotropies are observed in the lattice compression curves especially for R Ho and Tm; the c-axis is more compressible than the a-axis. On the other hand, the anisotropy in the lattice compression is found to be relatively small for R = Y and Lu. The close relation between T-C and c/a is pointed out particularly for R = Ho.