High-pressure Raman spectroscopy and lattice-dynamics calculations on scintillating MgWO4: A comparison with isomorphic compounds

Abstract

Raman scattering measurements and lattice-dynamics calculations have been performed on magnesium tungstate under high pressure up to 41 GPa. Experiments have been carried out under a selection of different pressure-media. The influence of non-hydrostaticity on the structural properties of MgWO4 and isomorphic compounds is examined. Under quasi-hydrostatic conditions a phase transition has been found at 26 GPa in MgWO4. The high-pressure phase has been tentatively assigned to a triclinic structure similar to that of CuWO4. We also report and discuss the Raman symmetries, frequencies, and pressure coefficients in the low- and high-pressure phases. In addition, the Raman frequencies for different wolframites are compared and the variation of the mode frequency with the reduced mass across the family is investigated. Finally, the accuracy of theoretical calculations is systematically discussed for MgWO4, MnWO4, FeWO4, CoWO4, NiWO4, ZnWO4, and CdWO4.

36 pages, 9 figures, 4 tables

References in corpus (9)

• Pressure-induced alpha-to-omega transition in titanium metal: A systematic study of the effects of uniaxial stress
• Pressure effects on the structural and electronic properties of ABX4 scintillating crystals
• Optical absorption of divalent metal tungstates: Correlation between the band-gap energy and the cation ionic radius
• High-pressure structural study of the scheelite tungstates CaWO4 and SrWO4
• Combined Raman scattering and ab initio investigation of pressure-induced structural phase transitions in the scintillator ZnWO4
• High-pressure structural phase transitions in CuWO4
• High-pressure phase transitions and compressibility of wolframite-type tungstates
• Local symmetry and magnetic anisotropy in multiferroic MnWO4 and antiferromagnetic CoWO4 studied by soft x-ray absorption spectroscopy
• Structural stability of Fe5Si3 and Ni2Si studied by high-pressure x-ray diffraction and ab initio total-energy calculations

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• Room-temperature vibrational properties of multiferroic MnWO4 under quasi-hydrostatic compression up to 39 GPa
• Inelastic Neutron Scattering Studies of Phonon Spectra and Simulations in Tungstates, AWO4 (A = Ba, Sr, Ca and Pb)
• High-pressure characterization of multifunctional CrVO4
• In-situ high-pressure Raman scattering studies in PbWO4 up to 48 GPa