Lattice and orbital fluctuations in TiPO4

Article

关键词: QUANTUM SPIN SYSTEMS;    LIGHT-SCATTERING;    CUGEO3;    VPO4;    PHOSPHATES;    TRANSITION;    CONSTANTS;    SPECTRA;    NUCLEAR;   

DOI  :  10.1103/PhysRevB.88.205136

来源: SCIE

【 摘 要 】

In the s = 1/2 antiferromagnetic spin chain material TiPO4, the formation of a spin gap takes place in a two-step process with two characteristic temperatures, T * = 111 K and T-SP = 74 K. We observe an unusual lattice dynamics over a large temperature regime as well as evidence for an orbital instability preceding the spin-Peierls transition. We relate different intrachain exchange interactions of the high temperature compared to the spin-Peierls phase to a modification of the orbital ordering pattern. In particular, our observation of a high-energy excitation of mixed electronic and lattice origin suggests an exotic dimerization process different from other spin-Peierls materials.

【 授权许可】

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