Mean-field type Ising spin glass in a diluted rare-earth intermetallic compound

Abstract

We have investigated a phase transition of a long-range RKKY Ising spin glass DyxY1−xRu2Si2 by means of the dc and the ac magnetization measurements. The static nonlinear susceptibility χ2 exhibits a divergent behavior toward Tg = 1.925 K with the exponent of γ = 1.08. The characteristic relaxation time τ obtained from the ac magnetization measurements also diverges to the same Tg with the exponent of zν = 1.9 in zero static field . These results indicate the spin glass phase transition belonging to the mean-field universality class, in which the exponents of γMF and (zν)MF are 1 and 2 respectively. Moreover, we observed the divergence of τ in a finite field of 500 Oe toward Tg = 1.412 K with the exponent of zν = 2.1, being quite similar to that in zero field. It strongly suggests an existence of the spin glass phase transition in a finite field and the replica symmetry breaking (RSB) in the long-range Ising spin glass DyxY1−xRu2Si2.