Studies of the magnetic behavior of the spinel system GaxCoCrFe1−xO4 by neutron diffraction

Abstract

Temperature dependent neutron diffraction studies have been done on the spinel series GaxCoCrFe1−xO4 with x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0. Magnetic properties of the system have been determined from the analysis of neutron data recorded at a number of temperatures. The sublattice and net magnetizations and the paramagnetic transition temperatures of all the members of the series have been found out. A decreasing ferrimagnetic order with increasing x is apparent from the progressive loss of magnetization and transition temperature. Evidence of magnetic spin clusters has been revealed from the reduced sublattice moments and diffuse signal appearing below the (1 1 1) Bragg peak at low temperature neutron patterns. A weak magnetic ordering has also been revealed from the magnetization measurements on the sample x=1.0. The system has been found to exhibit a complex magnetic phenomenon in which short-range magnetic spin clusters are superimposed on the ferrimagnetic long-range order together with a little extension of the short-range ordering of spin clusters at very low temperatures giving rise to a weak (2 0 0) superlattice reflection.