Neutron-scattering study of stripe-phase order of holes and spins in La1.48Nd0.4Sr0.12CuO4

We present a neutron diffraction study of charge and spin order within the CuO2 planes of La1.48Nd0.4Sr0.12CuO4, a crystal in which superconductivity is anomalously suppressed. At low temperatures we observe elastic magnetic superlattice peaks of the type (1/2+/-epsilon 1/2,0) and charge-order peaks at (2+/-2 epsilon,0,0), where epsilon=0.118. After cooling the crystal through the low-temperature-orthorhombic (LTO) to low-temperature-tetragonal (LTT) phase transition near 70 K, the charge-order peaks appear first at similar to 60 K, with the magnetic peaks appearing below 50 K. The magnetic peaks increase in intensity by an order of magnitude below 3 K due to ordering of the Nd ions. We show that the observed diffraction features are consistent with stripe-phase order, in which the dopant-induced holes collect in domain walls that separate antiferromagnetic antiphase domains. The Q dependence of the magnetic scattering indicates that the low-temperature correlation length within the planes is substantial (similar to 170 Angstrom), but only very weak correlations exist between next-nearest-neighbor planes. Correlations between nearest-neighbor layers are frustrated by pinning of the charge stripes to the lattice distortions of the LTT phase. The spin-density-wave amplitude corresponds to a Cu moment of 0.10+/-0.03 mu(B). The behavior of the electrical resistivity within the LTT phase is examined, and the significance of stripe-phase correlations for understanding the unusual transport properties of layered cuprates is discussed.