Magnetic properties of chiral magnets with impurities

Abstract

In the framework of the spin-lattice model we investigate a role of impurity doping on the evolution of the magnetic susceptibility and the development of the magnetic moment in magnetic field in chiral magnets. We focus on a particular class of silicide---Fe- and Co-doped MnSi. We introduce two feasible models accounting for different possible impurity arrangements in a real compound. Our calculations are based on the Monte Carlo method for classical spins. We are interested in the magnetic response and the degradation of the magnetic phase transition upon doping. We compare the calculated susceptibility with available experimental data in these compounds. We illustrate features of the behavior of the magnetic susceptibility by the corresponding spin patterns showing the deterioration of the spiral structure with temperature and the corresponding formation of ring-shape patterns in Bragg intensity profiles.