Monte Carlo studies of the spin-glass-like phase in Fe0.25Zn0.75F2

Monte Carlo results on the three-dimensional randomly-diluted Ising antifer romagnet FexZn1-xF2 indicate that its spin-glass-like phase at x=0.25 and z ero magnetic field is characterized by the presence of finite antiferromagn etic domains, separated by random vacancies, but strongly correlated in tim e. The glassy behavior is a consequence of the combined action of short-ran ge interactions and the presence of strong density fluctuations in the high ly diluted regime, close to the percolation concentration. By studying the aging of the system, we also find that its dynamics is much alike that of t heoretical spin-glass models. (C) 2000 American Institute of Physics. [S002 1-8979(00)68608-5].