Monte Carlo study of the two-dimensional quadratic Ising ferromagnet with spins<i>S</i>=1/2 and<i>S</i>=1 and with crystal-field interactions

Abstract

The single-spin-flip Metropolis Monte Carlo algorithm is applied to an Ising ferromagnet with mixed spins of S=1/2 and S=1 and a crystal-field interaction. The critical temperatures and exponents both in the absence and presence of the crystal-field interaction are investigated with finite-size scaling theory. The critical temperature that we obtained in zero crystal field is very close to the high-temperature series-expansion result. The finite-size scaling results for the critical exponents yield the two-dimensional Ising-model values, which are in good agreement with those suggested by the universality hypothesis. The phase diagram of this model is obtained and comparisons are made with other approximate methods when available.