Diluted cubic spin ice model

In this paper we consider a model of Ising-like point dipoles located on the edges of a simple cubic lattice. The temperature behaviour of heat capacity, magnetization and magnetic susceptibility in the nearest-neighbour model and the model with a limited long-range interaction radius is obtained by the Metropolis method. Three thermodynamic magnetic phases are present in the system: long-range order, short-range order, and disorder. The long-range order phase is absent in the nearest-neighbour model. The short-range order phase is characterised by a high level of entropy induced by the lattice geometry. An external magnetic field along one of the basis axes leads to the competition of order parameters in the model with a limited long-range interaction radius, and to the disappearance of residual entropy as a heat capacity peak in the nearest-neighbour model. The nonlinear dependence of the critical temperature of heat capacity on the concentration of dilution of the system by nonmagnetic vacancies in the nearest-neighbour model is shown.