LOCAL-MEAN-FIELD NUMERICAL-STUDIES IN FEXZN1-XF2

We study the diluted antiferromagnet FexZn1-xF2 by using a local-mean- field microscopical numerical approach in the whole range of magnetic concentrations with focus on the random-exchange Ising model and rando m-field Ising model-like behaviors at moderate dilutions. We investiga te the role of frustration, random vacancies, and magnetic-held cycles on properties such as irreversibility, metastability, domain nucleati on, growth, and pinning. The analysis includes studies on microscopic configurations, distribution of spins, and local effective fields, as well as, the computation of thermodynamical quantities such as the sta ggered and total magnetizations, the Edwards-Anderson parameter, and t he crossover exponent at x = 0.48. The very recent experimental sugges tion for a characteristic concentration, above which no domains are pr esent in the system, is also supported by our numerical studies. In ge neral, the results reported in this article are in a good agreement wi th the experimental ones.