Magnetic field induced anisotropy of 139La spin-lattice relaxation rates in stripe ordered La1.875Ba0.125CuO4
Magnetic field induced anisotropy of 139La spin-lattice relaxation rates in stripe ordered La1.875Ba0.125CuO4
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DOI：
10.1103/physrevb.92.155144
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发表时间：
2015-10-26
影响因子：
3.7
通讯作者：
Grafe, H-J
中科院分区：
文献类型：
--
作者：
Baek, S-H;Utz, Y.;Grafe, H-J
我们报告的La-139核磁共振研究进行了La 1.875Ba 0.125CuO 4单晶。结果表明，该材料的结构相变（高温四方相→低温正交相→低温四方相）为位移型。La-139的自旋-晶格弛豫速率T-1（-1）在电荷有序温度T-CO = 54 K时急剧上升，表明电荷有序引起自旋涨落的减慢。在自旋有序温度T-SO = 40 K以下，T-1（-1）的详细温度和场依赖性揭示了平行于[001]的H的自旋有序态中增强的自旋涨落的发展，这在沿着CuO 2平面的大场下被完全抑制。我们的结果揭示了在电荷和自旋条纹有序铜酸镧中不寻常的自旋涨落。
We report La-139 nuclear magnetic resonance studies performed on a La1.875Ba0.125CuO4 single crystal. The data show that the structural phase transitions (high-temperature tetragonal -> low-temperature orthorhombic -> low-temperature tetragonal phase) are of the displacive type in this material. The La-139 spin-lattice relaxation rate T-1(-1) sharply upturns at the charge-ordering temperature T-CO = 54 K, indicating that charge order triggers the slowing down of spin fluctuations. Detailed temperature and field dependencies of the T-1(-1) below the spin-ordering temperature T-SO = 40 K reveal the development of enhanced spin fluctuations in the spin-ordered state for H parallel to [001], which are completely suppressed for large fields along the CuO2 planes. Our results shed light on the unusual spin fluctuations in the charge and spin stripe ordered lanthanum cuprates.