Inhomogeneous magnetism in electron doped cuprates

We performed μ +SR experiments on polycrystalline specimens of Nd 2− y Ce y CuO 4 and Pr 2− y Ce y CuO 4 with Ce content y= 1 8 . From the viewpoint of μ +SR, both compounds show nearly the same behaviour. Long range magnetic order has been observed below 90 K, which is reflected in the onset of a spontaneous muon spin precession in zero magnetic field. The onset of a broad frequency distribution at 30 K is ascribed to the appearance of inhomogeneous magnetic order in the CuO 2 planes below this temperature. The comparison of the two samples proves that the Nd 3+ magnetic moment is not involved on this anomaly.