Abstract
Neutron - diffraction studies show that the magnetic structure of is either (a) type-III antiferromagnetic or (b) a complex noncollinear structure associated with a wave vector . We use group-theoretical methods and renormalization-group techniques to discuss the critical behavior associated with the transition to the magnetic structure (b). It is shown that this transition is described by an anisotropic component vector model which possesses a stable fixed point. The compound is predicted to belong to the same universality class as Ir, Tb, Nd, and Mn. This is in marked contrast to the transition to structure (a) which has previously been predicted, on the basis of the Landau theory, to be of first order.
- Received 20 June 1977
DOI:https://doi.org/10.1103/PhysRevB.17.4477
©1978 American Physical Society