ELECTRICAL AND MAGNETIC STUDIES OF CUXCOYCRZSE4 SINGLE-CRYSTALS

The electrical and magnetic properties of the spinels with the general chemical formula of Cu,Co,Cr,Se, (where y = 0.06, 0.1, 0.11 and 0.23) have been studied. Ferromagnetic ordering with a Curie temperature of 340 K, a Curie-Weiss paramagnetic temperature of 350 K and the p-type metallic conductivity were established for samples with low Co conten t y (up to 0.11). The sample with the highest Co content (y = 0.23) sh owed a ferrimagnetic behavior and n-type electrical semiconductivity. These effects are interpreted in terms of the magnetic double exchange and the Kramers Anderson super-exchange interactions and low spin sta te configurations of cations including non-stoichiometry. (C) 1998 Els evier Science B.V. All rights reserved.