Magnetic Properties of Laves Phase RRu₂Compounds (R=Gd, Tb, Dy, Ho and Er)

Abstract

Magnetic studies have been performed on single crystals of the C-14 type Laves phase RRu 2 (R=Gd, Tb, Dy, Ho and Er) and the pseudo-binary (R 1- x Y x )Ru 2 (R=Tb, Dy, Ho and Er) compounds in the temperature rarxge from 4.2 K to 300 K. DyRu 2 shows a transition from cone structure to ferromagnetic one at 15 K and the other RRu 2 compounds exhibit ferromagnetism. The magntetization curves of the RRu 2 single crystals show their own characteristic behaviors dependent on the sort of R atoms. Lower moments for all RRu 2 compounds except GdRu 2 are observed at 4.2 K. The results are interpreted in terms of the single ion Hamiltonian including applied field, molecular field and crystal electric field (CEF) terms. From the analysis, the B n m ( n ≧4) terms were found to be dominant in this system. Tlne bi-quadratic exchange interaction seems to contribtate to magnetic properties in TbRu 2 and DyRu 2 .