Evidence for room temperature ferromagnetism in CuxZn1-xO from magnetic studies in CuxZn1-xO/CuO composite

摘要

Magnetic studies in bulk 57 CuxZn1-xO/43 CuO composite prepared chemically with x=0.10 (0.03) are reported. Temperature dependence of the magnetic susceptibility shows clear signature of the Neel temperature T-N similar or equal to 230 K for pure CuO. Hysteresis loop studies in the zero-field-cooled sample show room-temperature ferromagnetism with coercivity H-c similar or equal to 50 Oe at 300 K with strong temperature dependence for T 0 at T-N=230 K of CuO. These results and the temperature dependence of remanence M-r provide strong evidence that the CuxZn1-xO phase with x similar or equal to 0.10 is a ferromagnet with T-c similar or equal to 400 K. An electron magnetic resonance signal due to Cu2+ substituting for Zn2+ in CuxZn1-xO is also observed. (c) 2007 American Institute of Physics.