Latent paramagnetism in trigonal compounds

An anomalous dependence of the magnetization M as a function of magnetic field H in hexagonal crystals of AFeCs3 (A= Cs, Rb) is explained by the macroscopic theory. It is shown that the first of two magnetization jumps on the M(H) curve results from the occurrence of a state with latent paramagnetism, in which one of three sublattices of the effective magnetic field is compensated. The compensation is shown to occur only in the basal plane. A linear run of the M(H) dependence in the region of the first jump is explained by a declination of octahedrons consisting of chloride ions of the paramagnetic sublattice during the antiferromagnetic ordering of two, out of three, sublattices.