Spin-Peierls distortions in TiPO4

Article

关键词: TOTAL-ENERGY CALCULATIONS;    WAVE BASIS-SET;    MAGNETIC-PROPERTIES;    ANHYDROUS PHOSPHATES;    NEUTRON-DIFFRACTION;    SUPERSPACE GROUPS;    TRANSITION;    BEHAVIOR;    NUCLEAR;    METALS;   

DOI  :  10.1103/PhysRevB.88.184420

来源: SCIE

【 摘 要 】

On the basis of single-crystal x-ray diffraction we show that TiPO4 undergoes a spin-Peierls distortion below 74.5(5) K, with a dimerization of the Ti chains along the c axis. Between 74.5(5) and 111.6(3) K, TiPO4 develops an incommensurate (IC) phase with temperature-dependent q vector (sigma(1),0,0). Density functional calculations strongly suggest that the IC phase results from a frustration of the lock-in spin-Peierls transition due to the competition of three energetically almost degenerate crystal structures and elastic coupling of the Ti chains via the bridging PO4 units. The phase transition into the IC phase is of second order, but the lock-in transition into the spin-Peierls distortion below 74.5 K is of weak first order in nature.

【 授权许可】

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