Spin Glass and Antiferromagnetic Behaviour in a Diluted fcc Antiferromagnet

TL;DR

This study uses Monte Carlo simulations to investigate how dilution affects the magnetic phases of a frustrated fcc antiferromagnet, revealing a spin glass phase at certain concentrations and phase transition behaviors.

Contribution

It provides the first detailed Monte Carlo analysis of spin glass and antiferromagnetic transitions in a diluted fcc antiferromagnet, including critical exponents and phase diagram insights.

Findings

Spin glass transition occurs for spin concentration p<0.75.

Divergent spin glass susceptibility and correlation length observed.

First order to continuous phase transition identified between p=0.85 and p=0.75.

Abstract

We report on a Monte Carlo study of a diluted Ising antiferromagnet on a fcc lattice. This is a typical model example of a highly frustrated antiferromagnet, and we ask, whether sufficient random dilution of spins does produce a spin glass phase. Our data strongly indicate the existence of a spin glass transition for spin--concentration $p<0.75$: We find a divergent spin glass susceptibility and a divergent spin glass correlation length, whereas the antiferromagnetic correlation length saturates in this regime. Furthermore, we find a first order phase transition to an antiferromagnet for $1\ge p>0.85$, which becomes continuous in the range $0.85>p>0.75$. Finite size scaling is employed to obtain critical exponents. We compare our results with experimental systems as diluted frustrated antiferromagnets as ${\rm Zn_{1-p}Mn_{p}Te}$.