Inhomogeneous spin order in the magnetic phase of electron-doped high-Tc superconductors

Abstract Zero-field μ + SR experiments have been performed on polycrystalline samples Nd 2− y Ce y CuO 4 and Pr 2− y Ce y CuO 4 with y =0.10 and 0.125. An inhomogeneous distribution of internal fields is found in the magnetically ordered phases below T≈100 K . A distinct two-peak structure in the Fourier spectra is observed for all compounds below T≈80 K . Our findings are traced back to inhomogeneous Cu 2+ spin order, which can be understood in terms of an electronic phase separation. The results are discussed in comparison with the one-dimensionally modulated charge and spin order found in the hole-doped cuprate La 2− x − y R x Sr y CuO 4 (R=Nd, Eu) at charge carrier concentrations around y =0.125.