Spin- and charge-density-wave orders in La 1.87Sr 0.13Cu 0.99Fe 0.01O 4

Abstract

We have performed elastic neutron-scattering measurements on La 1.87Sr 0.13Cu 0.99Fe 0.01O 4 to study the magnetic impurity effects on the stripe correlations in high- T c cuprates. Both charge-density-wave (CDW) and spin-density-wave (SDW) orders are observed in the low-temperature-orthorhombic (LTO) phase for the first time. With decreasing the temperature, CDW order first appears at ∼ 60 K followed by the SDW order at lower temperature of ∼ 50 K . The incommensurability for the CDW order ( ε ) was found to be 0.224 ± 0.002 r.l.u., which is approximately twice of that for SDW order ( δ ) of 0.115 ± 0.003 r.l.u. Both ordering sequence and relation of ε ≈ 2 δ are the same for SDW and CDW orders observed in the low-temperature-tetragonal (LTT) phase of La 1.60 - x Nd 0.4 Sr x CuO 4 (LNSCO), suggesting that the similar stripe correlations exist in the cuprate oxides, irrespective of crystal structure.