Spin-glass and antiferromagnet critical behavior in a diluted fcc antiferromagnet

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 p0.75: 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\ensuremath{\ge}p\ensuremath{\gtrsim}0.85, which becomes continuous in the range 0.85\ensuremath{\gtrsim}p\ensuremath{\gtrsim}0.75. Finite-size scaling is employed to obtain critical exponents. We compare our results with experimental systems as diluted frustrated antiferromagnets as ${\mathrm{Zn}}_{1\mathrm{\ensuremath{-}}\mathit{p}}$${\mathrm{Mn}}_{\mathit{p}}$Te. \textcopyright{} 1996 The American Physical Society.