Fermi surface of Pd and Pt under homogeneous strain.

Abstract

The response of the Fermi surface (FS) of the transition metals palladium and platinum to a homogeneous uniaxial deformation of the lattice has been investigated in detail experimentally and theoretically. The uniaxial-stress dependence of several extremal cross-sectional areas of the Fermi surface of $_{46}\mathrm{Pd}$ and $_{78}\mathrm{Pt}$ were obtained by a simultaneous measurement of the oscillatory magneto- striction and the de Haas--van Alphen torque. For six of the seven experimentally studied orbits in Pd, all the uniaxial-stress derivatives were determined and their sum compares well with the direct measurements of the hydrostatic-pressure derivatives by other authors. In Pt, four orbits on all three Fermi-surface sheets were investigated. Our result for the hydrostatic-pressure dependence of the \ensuremath{\Gamma}-centered electron orbit is again in agreement with a previously published direct estimate. From the experiments, the response of the FS to volume-conserving tetragonal shears and volume changes has been extracted and compared with self-consistently computed tetragonal shear (and, for Pt, volume) derivatives. The calculations, done with the linear combination of muffin-tin orbitals method, show that the discrepancy between theory and experiment for the shear response cannot be attributed to a failure of the rigid-muffin-tin approximation, as was stated in earlier work.