Experimental and theoretical study of structural properties and phase transitions in YAsO4 and YCrO4

Article

关键词: X-RAY-DIFFRACTION;    SINGLE-CRYSTAL;    LATTICE-PARAMETERS;    RAMAN-SPECTRA;    ZIRCON;    SCHEELITE;    ENERGY;    ZRSIO4;    METAL;   

DOI  :  10.1103/PhysRevB.83.134109

来源: SCIE

【 摘 要 】

We have performed experimental and theoretical studies of the structural stability of YAsO4 and YCrO4 at high pressures. X-ray-diffraction experiments together with ab initio total-energy and lattice-dynamics calculations have allowed us to completely characterize a pressure-induced structural phase transition from the zircon to the scheelite structure in both compounds. Furthermore, total-energy calculations have been performed to check the relative stabilities of different candidate structures at different pressures and allow us to propose for YAsO4 the zircon -> scheelite -> SrUO4-type sequence of structures. In this sequence, sixfold arsenic coordination is attained for the SrUO4-type structure above 32 GPa. The whole sequence of transitions is discussed in comparison with YVO4, YPO4, YNbO4, YMoO4, and YTaO4. Also a comparative discussion of lattice-dynamics properties is presented. The band gap for YAsO4 and YCrO4 and the band structure for YAsO4 are also reported. Finally, the room-temperature equation of state of different compounds is also obtained.

【 授权许可】

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