Symmetry Considerations in the Determination of Magnetic Structures

Abstract

The connection between magnetic structures and the symmetry of the crystal lattice is investigated in the zero-temperature limit. It is assumed that the magnetic energy is bilinear in the magnetic moments and has the full symmetry of the lattice. A standard group theoretical analysis leads to magnetic configurations belonging to irreducible representation of the space group. The requirement that equivalent magnetic moments have equal magnitude is treated as a set of subsidiary conditions. When these conditions can be fulfilled within one irreducible representation, one gets magnetic structures which are time independent for symmetry reasons.