Influence of vacancies on the temperature-dependent magnetism of bulk Fe: A spin-lattice dynamics approach

The effect of random vacancies on the magnetic properties of a bcc Fe sample is studied using classical coupled spin-lattice dynamics. This simulation technique is based on molecular dynamics of the atoms coupled to a classical dynamics of the spin system. We show that the presence of vacancies lowers the Curie temperature of the system. This result is in qualitative agreement with studies of Ising systems with random non-magnetic defects. However, magnetic moments are increased in the vicinity of vacancies. When this effect is included in our simulation using a core-bulk model, the vacancy effects are reduced, albeit without reaching the values of an ideal lattice.