Spin canting and lattice symmetry in La2CuO4

Article

关键词: ANISOTROPIC SUPEREXCHANGE INTERACTION;    WEAK FERROMAGNETISM;    TRANSITION;    PHASE;    MAGNETISM;    ANTIFERROMAGNETISM;    SUPERCONDUCTIVITY;    CONDUCTIVITY;    STATE;    GAPS;   

DOI  :  10.1103/PhysRevB.107.094413

来源: SCIE

【 摘 要 】

While the dominant magnetic interaction in La2CuO4 is superexchange between nearest-neighbor Cu moments, the pinning of the spin direction depends on weak anisotropic effects associated with spin-orbit coupling. The symmetry of the octahedral tilt pattern allows an out-of-plane canting of the Cu spins, which is compensated by an opposite canting in nearest-neighbor layers. A strong magnetic field applied perpendicular to the planes can alter the spin canting pattern to induce a weak ferromagnetic phase. In light of recent evidence that the lattice symmetry is lower than originally assumed, we take another look at the nature of the field-induced spin-rotation transition. Comparing low-temperature neutron diffraction intensities for several magnetic Bragg peaks measured in fields of 0 and 14 T, we find that a better fit is provided by a model in which spins rotate within both neighboring planes but by different amounts, resulting in a noncollinear configuration. This model allows a more consistent relationship between lattice symmetry and spin orientation at all Cu sites.

【 授权许可】

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