Lattice dynamical analogies and differences between SrTiO3 and EuTiO3 revealed by phonon-dispersion relations and double-well potentials

Article

关键词: 110 DEGREES K;    SPIN-EXCHANGE INTERACTIONS;    ELECTRON-PARAMAGNETIC-RESONANCE;    PHASE-TRANSITION;    STRONTIUM-TITANATE;    FERROELECTRICITY;    MODES;    STABILITY;    SOLIDS;    ORIGIN;   

DOI  :  10.1103/PhysRevB.84.184114

来源: SCIE

【 摘 要 】

A comparative analysis of the structural phase transitions of EuTiO3 and SrTiO3 ( at T-S = 282 and 105 K, respectively) is made on the basis of phonon-dispersion and density functional calculations. The phase transition of EuTiO3 is predicted to arise from the softening of a transverse acoustic zone boundary mode caused by the rotations of the TiO6 octahedra, as also found for the phase transition of SrTiO3. Although the temperature dependence of the soft mode is similar in both compounds, their elastic properties differ drastically because of a large difference in the double-well potentials associated with the soft zone boundary acoustic mode.

【 授权许可】

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