MAGNETIC-PROPERTIES OF NEW OXIDES OF THE TYPE R2BA2CUPTO8 (R = ER ANDLU)

The magnetic properties of these oxides have been studied by means of the magnetic susceptibility and magnetization measurements. Luthetium oxide behaves as an antiferromagnetic compound and the estimated Neel temperature is 5.2 K. However, the isostructural Er2Ba2CuPtO8 is a fer romagnetic compound with a Curie temperature close to 25 K. The satura tion magnetic moment obtained is 9.71 BM, lower than that expected for this oxide. The net maximum observed in the magnetic susceptibility a t 3 K and the metamagnetic transition detected at 2 K in the M vs. H m easurement are indicative of the magnetic phase transition from ferrom agnetic to antiferromagnetic state. (C) 1998 Elsevier Science S.A.