Reentrant spin-glass transition in a dilute Heisenberg ferromagnet

Abstract We perform a large-scale Monte Carlo simulation of a dilute ferromagnetic Heisenberg model with antiferromagnetic next-nearest neighbor interactions. We find that the model reproduces a reentrant spin-glass (RSG) transition. That is, as the temperature is decreased, the magnetization M once increases rapidly below a certain temperature, reaches a maximum value, and then disappears at some lower temperature. The low-temperature phase is suggested to be a spin-glass (SG) phase that is characterized by ferromagnetic clusters. We present a possible mechanism responsible for the RSG transition.