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We report the results on x-ray diffraction and magnetic susceptibility study of Y-Ba-CCu^ScJ-O. The materials were prepared in a stoichiometry corresponding to Y1Ba2(Cu1_;cSc;t)3O7. Although x-ray analysis reveals the increasing presence of a subtle second phase with increasing Sc content, the superconducting transition temperature and resistivity did not change substantially in the composition range 0.0 =s x ^ 0.15. In contrast, the magnetic susceptibility studies showed dramatic changes. Although Sc3+ has no spin by itself, an enhanced paramagnetic Curie susceptibility was observed above Tc with a moment of 1.5 /AB per Sc. At 16 K a sharp cusp is observed in the temperature dependent susceptibility corresponding to the onset of a three-dimensionally ordered antiferromagnetic state. These results are discussed in terms of an additional previously unreported phase of Y-Ba-(Cu-Sc)-O that has an antiferromagnetic Neel temperature of 16 K. For composition of x = 1.0, a new phase is formed which is nonmagnetic.

We report the magnetization M as a function of magnetic field H and temperature T for both semiconducting La2-xSrxCuO4-y and Y1Ba2Cu3O6+x. An anomalous magnetic field dependence has been observed for each of these samples. Below TN, the application of high field at small x (< 0.02) for La2-xSrxCuO4-y and for Y1Ba2Cu3O6+x at x = 0, there is an anomalous behavior for M (H), suggestive of a presence of a ferromagnetic component. For Y1Ba2Cu3O6+x samples of x = 0.25 and 0.34, there is a sublinear behavior of M on H. Possible odels are discussed for these novel phenomena