INFLUENCE OF GA SUBSTITUTION ON THE MAGNETIC-ORDERING OF ND IONS IN NDBA2CU3-XGAXO7-Y AT LOW-TEMPERATURES

The temperature dependence of magnetic specific heat and magnetic susc eptibility of Ga substituted Nd-123 compounds has been investigated at low temperatures. The magnetic ordering of the Nd3+ ions changes rema rkably with the Ga concentration. The nature of the magnetic ordering is analysed using different magnetic models. The results are compared with those reported for pure unsubstituted NdBa2Cu3O7-y samples with v arious oxygen, contents. The magnetic susceptibility data are analysed in the light of crystalline electric field effect (CEF) of different symmetry. The importance of CEF effects in determining the nature of m agnetic ordering is explained.