Non-collinear ferrimagnetic phases in the Fe2?xMnxAs system

The stabilization mechanisms of non-collinear magnetically ordered phases observed in the Fe2-xMnxAs system with 1.19 less than or equal to x less than or equal to 1.365 are considered within the framework of a model approach that uses the number of d-electrons and the form of density of their electron states, obtained from ab initio calculations. It is found that the energy stability of non-collinear structures and the kind of order-order phase transitions are determined by electron filling of the d-band and by the form of density of d-electron states, which depend on the manganese content. It is demonstrated that the pressure features of spontaneous and magnetic field-induced order-order transitions are related to a character of renormalization of the electronic structure under pressure.