MAGNETIC DOMAIN BEHAVIOR OF CU-FERRITE DOPED WITH SMALL QUANTITIES OFCD OR BE IONS

The temperature dependences of the ac-initial susceptibility chi(ac)(T ) of a Cu1-xMexFe2O4 ferrospinel system with Me = Cd/Be (size effect) and x = 0.05 were performed in 300 - 1100 K range. A remarkable therma l treatment cycling effects were observed. The temperatures of blockin g effect, Hopkinson effect, spontaneous spin-reorientation phase trans ition and Curie temperature were determined. The irreversible magnetic domain behaviour of Cu-Cd/Be ferrite system with single domain and mu ltidomain particles were explained on the basis of cooperative Jahn-Te ller effect (accompanied by ionic diffusion), magnetic anisotropy of t his system and properties of magnetic particles.