Crystal structure and high-field magnetism of La2 Cu O4
Crystal structure and high-field magnetism of La2 Cu O4
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DOI：
10.1103/physrevb.73.144513
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发表时间：
2006-01
影响因子：
3.7
通讯作者：
M. Reehuis;C. Ulrich;K. Prokeš;A. Gozar;A. Gozar;Girsh Blumberg;S. Komiya;Y. Ando;Philip Pattison;Philip Pattison;B. Keimer
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文献类型：
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作者：
M. Reehuis;C. Ulrich;K. Prokeš;A. Gozar;A. Gozar;Girsh Blumberg;S. Komiya;Y. Ando;Philip Pattison;Philip Pattison;B. Keimer
用中子衍射法测定了La_2CuO_4单晶在外加磁场和未外加磁场条件下的晶体结构和磁有序模式。一个以前未报道的，微妙的单斜晶系的晶体结构偏离正交空间群BMAB的扭曲被检测到。这种畸变也存在于轻掺Sr晶体中。的晶体结构的细化表明，从正交对称性的偏差主要是确定驱动连续的重新取向的铜自旋从正交B轴的c轴，直接确认预测的基础上先前的磁阻和拉曼散射实验。还观察到了非化学计量La_2CuO_4的c轴取向场引起的自旋翻转跃迁，但跃迁场11.5T明显大于以前的工作。
Neutron diffraction was used to determine the crystal structure and magnetic ordering pattern of a La2CuO4 single crystal, with and without applied magnetic field. A previously unreported, subtle monoclinic distortion of the crystal structure away from the orthorhombic space group Bmab was detected. The distortion is also present in lightly Sr-doped crystals. A refinement of the crystal structure shows that the deviation from orthorhombic symmetry is predominantly determined to drive a continuous reorientation of the copper spins from the orthorhombic b axis to the c axis, directly confirming predictions based on prior magnetoresistance and Raman scattering experiments. A spin-flop transition induced by a c-axis oriented field previously reported for nonstoichiometric La2CuO4 is also observed, but the transition field 11.5 T is significantly larger than that in the previous work.