6533b834fe1ef96bd129d694
RESEARCH PRODUCT
High-pressure polymorphs of TbVO4: A Raman and ab initio study
Alfonso MuñozFrancisco Javier ManjónV. K. PanchalPlácida Rodríguez-hernándezSrungarpu N. AcharyDaniel ErrandoneaAvesh K. Tyagisubject
Phase transitionEquation of stateChemistryMechanical EngineeringMetals and AlloysAb initioFergusoniteCrystallographysymbols.namesakeMechanics of MaterialsAb initio quantum chemistry methodsPhase (matter)FISICA APLICADARaman spectroscopyMaterials ChemistrysymbolsOrthorhombic crystal systemAb initio calculationsPressure-driven transitionsRaman spectroscopyZircon oxidesMonoclinic crystal systemdescription
Raman measurements on TbVO4 show the occurrence of three pressure-induced phase transitions. The first one, an irreversible transition from the zircon to the scheelite structure, occurs beyond 6.7 GPa. In addition, two reversible transformations take place at 26.7 and 34.4 GPa. The last transition was never reported before. The experimental findings are supported by structural and lattice-dynamics calculations that helped us to identify the post-scheelite phase as a monoclinic fergusonite structure. According to the calculations, the third transition involves a symmetry increase. An orthorhombic structure is proposed for the phase found above 34.4 GPa. The results have been compared with previous studies in TbVO4 and discussed in comparison with related compounds. The calculated equations of state are reported for the different polymorphs of TbVO4. A compressibility increase is caused by the third transition. It is associated to a bond-strength decrease, which is related to a coordination increase and a delocalization of Tb f-electrons. (C) 2013 Elsevier B.V. All rights reserved.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2013-11-15 |