Lattice Dynamics of 尾-SnWO4: Experimental and Ab Initio Calculations

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• 作者：Justyna Wojcik ; Florent Calvayrac ; Fran莽ois Goutenoire ; Noureddine Mhadhbi ; Gwena毛l Corbel ; Philippe Lacorre ; Alain Bulou
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：March 14, 2013
• 年：2013
• 卷：117
• 期：10
• 页码：5301-5313
• 全文大小：810K
• 年卷期：v.117,no.10(March 14, 2013)
• ISSN：1932-7455

文摘

The vibrational properties of 尾-SnWO₄ at center of the Brillouin zone are investigated by Raman at low temperature and infrared spectroscopies in connexion with ab initio calculations. In this cubic structure archetype of new materials with ionic conductivity properties, all 29 optical modes predicted by group theory are Raman-active. All lines have been unambiguously identified on the basis of depolarization ratio measurements. The phonon spectrum is calculated at the center of the Brillouin zone by GGA pseudopotentials within the PWSCF/QE suite. A remarkable agreement is obtained with the experimental frequencies, and a fairly good one is also observed with the Raman scattering cross sections calculated using LDA pseudopotentials for the internal modes of WO₄^{2鈥?/sup> tetrahedra and the lattice modes as well. All Raman lines are assigned for the first time, and the normal coordinates characteristics are described. The whole results give a large credit to the calculation of the phonon spectra in this structural arrangement with such ions. The phonon density of states is deduced, and the characteristics are explained on the basis of the phonon dispersions curves along the [尉00] and [尉尉0] high-symmetry directions of the Brillouin zone.}