High-field low-temperature magnetisation curves of anisotropic ferrimagnets

Possible shapes of high-field magnetisation curves of two-sublattice ferrimagnets are analysed within a model with two anisotropy constants for the subdominant sublattice. The model is relevant to 3 d–4 f intermetallic compounds. For the purpose of classification the magnetisation curves are regarded as ordered sequences of horizontal, slanted and vertical sections, without reference to quantitative details. Every shape type corresponds to a domain in the plane of relative anisotropy parameters κ 1 and κ 2. The κ 1 κ 2 diagram proves rather complicated; however, in the limiting cases of very weak or very strong anisotropy (in relation to intersublattice exchange) it takes the same universal form characteristic of simple ferromagnets. ► Classification of patterns of high-field magnetisation curves. ► Each pattern occupies a domain in the parameter space of anisotropy constants. ► Relevance to 3 d–4 f intermetallic compounds.