Ferroquadrupole ordering of the ternary intermetallic compound Ce3Pd20Ge6

摘要

We have investigated the elastic properties of the ternary inter-metallic compound Ce3Pd20Ge6 with a Gamma(8) ground state by ultrasonic and dilatometric methods. A softening of 50% in the transverse (C-11 - C-12)/2 mode above T-Q = 1.25 K and a spontaneous lattice distortion DeltaL/L = 2.5 x 10(-4) along the [001] direction below T-Q indicate a structural transition from cubic to tetragonal (or orthorhombic) symmetry accompanied by O-2(0)- or O-2(2)-type ferroquadrupole ordering. The magnetic field dependence of (C-11 - C-12)/2 and the dilatation DeltaL/L along [001] are also presented. (C) 2002 Elsevier Science B.V. All rights reserved. [References: 7]