FERRIMAGNETS WITH A WEAK MAGNETIC SUBLATT ICE

Measurements of the anomalous temperature behaviour of the spontaneous magnetisation of various ferrimagnets (N-, M-, and P-type Neel curves ) are analysed and summarised. The concept of the weak magnetic sublat tice is applied to explain the anomalies as well as the low-temperatur e point T-B and the antiferromagnetic-type paraprocess. The paraproces s phenomenon causes sign anomalies in the magnetocaloric effect, magne tostriction, and the first component of the isotropic magnetoresistanc e. It is suggested that in magnetite (Fe3O4) the role of the weak subl attice is played by the spin-ordered subsystem of hopping electrons (' magneto-electron' sublattice), and the point T-B is nothing else but t he low-temperature transformation point T-t (100-120 K).