科研之友
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摘要
The empty perovskite ScF3 exhibits negative thermal expansion up to 1100 K. We demonstrate that ab initio calculations of temperature-dependent effective phonon spectra allow us to quantitatively describe the behavior of this compound and the suppression of negative thermal expansion. Based on this result, we predict an anomalous temperature dependence of the thermal conductivity and interpret it as a general feature of the perovskite class. Finally, we comment on the fact that the suppression of negative thermal expansion at such a high temperature is beyond the reach of the quasiharmonic approximation and we discuss this suppression based on the temperature dependence of the mode Gruneisen parameters.
- 出版日期2016-7-25
- 单位中国地震局
