The symmetry of the incommensurate magnetic phase of ErFe4Ge2

Abstract

ErFe4Ge2 has below the Néel temperature two phases in competition, one with a commensurate and one with an incommensurate spin wave. The symmetry of the latter may be analysed in terms of irreducible representations, superspace groups and magnetic superspace groups. In this paper we compare these approaches. The relation with the commensurate structure is discussed.