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 \rightarrow scheelite \rightarrow 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 band structure for YAsO4 are also reported. Finally, the room-temperature equation of state of different compounds is also obtained.
@article{arxiv.1201.5249,
title = {Experimental and theoretical study of structural properties and phase transitions in YAsO4 and YCrO4},
author = {D. Errandonea and R. Kumar and J. Lopez-Solano and P. Rodriguez-Hernandez and A. Munoz and M. G. Rabie and R. Saez Puche},
journal= {arXiv preprint arXiv:1201.5249},
year = {2012}
}