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

TL;DR

This study investigates the phase transition of a long-range RKKY Ising spin glass in a diluted intermetallic compound, revealing mean-field universality class behavior and evidence of replica symmetry breaking.

Contribution

It provides experimental evidence of a spin glass phase transition in a finite field consistent with mean-field theory and RSB in a long-range Ising spin glass.

Findings

Divergent nonlinear susceptibility at Tg=1.925 K

Characteristic relaxation time diverges with exponent 1.9 in zero field

Evidence of spin glass transition and RSB in finite field

Abstract

We have investigated a phase transition of a long-range RKKY Ising spin glass \dyyrusi by means of the dc and the ac magnetization measurements. The static nonlinear susceptibility $\chi_{2}$ exhibits a divergent behavior toward $\Tg$ $=$ 1.925 K with the exponent of $\gamma$ $=$ 1.08. The characteristic relaxation time $\tau$ obtained from the ac magnetization measurements also diverges to the same $\Tg$ with the exponent of $z\nu$ $=$ 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 $\gammaMF$ and $\znuMF$ are 1 and 2 respectively. Moreover, we observed the divergence of $\tau$ in a finite field of 500 Oe toward $\Tg$ $=$ 1.412 K with the exponent of $z\nu$ $=$ 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 \dyyrusi.