Magnetic phase diagrams and magnetization curves of ferrimagnets with one unstable magnetic subsystem

Physical properties of RCo2Laves phases

“…If the magnetization of the unstable sublattice (M Co ) is less than that of the stable one (M R ) and simultaneously B M is less than the lower critical field B c1 , non-collinear magnetic structures will not appear. The system will become ferromagnetic through two IEM transitions: (i) a disappearance of the Co magnetic moment at a critical field B m1 and (ii) a re-entrant onset of the Co magnetic moment along the field direction at a field B m2 > B m1 (Dubenko et al 1996):…”

Phase transitions in megagauss magnetic fields

“…Thus, in ferrimagnetic RCo 2 compounds, there have to be observed two successive metamagnetic transitions associated with magnetization jumps during the processes of demagnetization and reentrant magnetization of the d subsystem in an external field. In pure RCo 2 compounds, these metamagnetic transitions have not been actually observed, since according to the estimates they would have to take place in magnetic fields in excess of 100 T. Nevertheless, metamagnetic transitions of this type have been realized experimentally and studied on substituted compounds (R,Y)(Co,Al) 2 and (R,Lu)(Co,Al) 2 , where they are shifted into the region of lower fields [6,7]. However, the phase diagrams of substituted compounds are more complex, since in these compounds metamagnetic transitions may`interfere' with transitions into the noncollinear ferrimagnetic phase [7 ± 9].…”