Compression of scheelite-type SrMoO4 under quasi-hydrostatic conditions: Redefining the high-pressure structural sequence

Abstract

The high-pressure behavior of tetragonal SrMoO 4 was analyzed by Raman and optical-absorption measurements. Pressures up to 46.1 GPa were generated using diamond-anvil cells and Ne or N 2 as quasi-hydrostatic pressure-transmitting media. A reversible phase transition is observed at 17.7 GPa. A second transition is found at 28.8 GPa and the onset of a third one at 44.2 GPa. The pressure dependence of Raman-active modes is reported for the different phases and the pressure evolution of the fundamental band-gap reported for the low-pressure phase. The observed changes in the Raman spectra contradict the structural sequence determined from previous experiments performed under higher non-hydrostaticity. This fact suggests that deviatoric stresses can influence pressure-driven transitions in scheelite-type oxides. We also report total-energy, lattice-dynamics, and band-structure calculations. They reproduce accurately the behavior of the physical properties of the low-pressure phase and predict the occurrence of phase transitions at pressures similar to experimental transition pressures. According to theory, the high-pressure phases have monoclinic and orthorhombic structures, which are much more compact than tetragonal scheelite. Theoretical results and experiments are compared with previous studies. V C 2013 American Institute of Physics.

Room-temperature vibrational properties of multiferroic MnWO4 under quasi-hydrostatic compression up to 39 GPa

“…Both facts suggest that deviatoric stresses could strongly influence the high-pressure structural and vibrational behavior of wolframites as they do on related scheelite-type oxides. 17,18 In Table I, Since the multiferroic behavior of MnWO 4 was discovered, many works have been devoted to study its physical properties. However, most of those properties have been studied in the low-temperature range where the magnetic behavior shows up.…”

High-Pressure Crystal Structure, Lattice Vibrations, and Band Structure of BiSbO4

“…We determined the frequency of each of the phonons of the doublet by making a Lorentzian multi-peak fitting analysis. 36 In order to illustrate this fact, we include in Figure 3 two insets (on the left-hand side) showing the asymmetric phonons and the two Lorentzian functions used to fit them.…”

“…1,4,7,8 During the last decade, intensive investigations have been carried out on the structural evolution of MTO 4 -type ternary oxides under high-pressure (HP). They showed that compression is an efficient tool to improve the understanding of the main physical properties of vanadates, 9 phosphates, 10 chromates, 11 tungstates, 12 molydbates, 13 arsenates, 14 and many other MTO 4 compounds. 15 However, to the best our knowledge, an investigation of BiSbO 4 under pressure is still lacking in literature.…”

Pressure-induced phase transition and band-gap collapse in the wide-band-gap semiconductorInTaO4

“…During the last decade, the most studied members of this family of materials have been the orthotungstates and orthomolybdates, which have many technological applications [11][12][13][14][15][16]. In special high-pressure (HP) studies of MTO 4 ternary oxides have generated a large amount of attention, with HP being an efficient tool in improving the understanding of their physical properties [3][4][5][6][7][8][9][10][11][12]. Recently, other compounds such as perrhenates [17] and orthotantalates [18] have also become the focus of research.…”

“…Ternary oxides of the form MTO 4 have been extensively studied for their interesting physical properties, in particular, those oxides crystallizing either in the scheelite or the wolframite structure [1][2][3][4][5][6][7][8][9][10]. During the last decade, the most studied members of this family of materials have been the orthotungstates and orthomolybdates, which have many technological applications [11][12][13][14][15][16].…”