Magnetism and transport properties of HfMSi (M5Pt, Pd) and

The crystallographic, electric, and magnetic properties of the new intermetallic compounds HfMSi (M5Pt or Pd) and the superconductivity of HfRh Pd Si were studied. The crystal structure of HfPtSi and HfPdSi could be refined assuming an orthorhombic 12 xx structure (space group Pnma) and lattice constants of a50.6549 nm, b50.3883 nm, and c50.7506 nm for HfPtSi and a50.6570 nm, b50.3874 nm, and c50.7565 nm for HfPdSi. Both compounds are metallic and show diamagnetic behavior below 300 K. A small effective electron mass is thought to be a reason for the diamagnetism of HfMSi (M5Pt or Pd). In the HfRh Pd Si system, the 12 xx superconductivity of HfRhSi (T 52.2 K) is suppressed by replacing Rh by Pd. The Pd content dependence of the Pauli paramagnetic c susceptibility suggests that reduction of the density of states at the Fermi level is a possible cause of the suppression of superconductivity in the HfRh Pd Si system. © 2000 Published by Elsevier Science S.A. All rights reserved. 12 xx