AgClO4 has been studied under compression by x-ray diffraction and density functional theory calculations. Experimental evidence of a structural phase transition from the tetragonal structure of AgClO4 to an orthorhombic barite-type structure has been found at 5.1 GPa. The transition is supported by total-energy calculations. In addition, a second transition to a monoclinic structure is theoretically proposed to take place beyond 17 GPa. The equation of state of the different phases is reported as well as the calculated Raman-active phonons and their pressure evolution. Finally, we provide a description of all the structures of AgClO4 and discuss their relationships. The structures are also compared with those of AgCl in order to explain the structural sequence determined for AgClO4.
@article{arxiv.1204.4335,
title = {Pressure-induced phase transitions in AgClO4},
author = {D. Errandonea and L. Gracia and A. Beltran and A. Vegas and Y. Meng},
journal= {arXiv preprint arXiv:1204.4335},
year = {2012}
}