Formation of non-collinear magnetic states in the Fe(2-x)Mn(x)As system

Within the frameworks of the model using ab initio calculation data on d-band filling and on the shape of density of d-electron states in Fe2-xMnxAs, the mechanisms of stabilization of non-collinear magnetic ordered phases observed within the range of 1.19 <= x <= 1.365 are considered. The relation between baric peculiarities of the changes in stability of noncollinear phases and changes in the electronic structure characteristics of Fe2-xMnxAs due to lattice deformation is disclosed. It is found that stabilization of non-collinear phases and change in type of order-order phase transition with decreasing manganese is determined by competition between the electronic filling of the d-band, shape of the d-electron density of states and structural features of these phases.