Valkovskiy G A, Mistonov A A, Smirnov M B, Grigoriev S V
Saint Petersburg State University, 7/9 Universitetskaya nab., Saint-Petersburg 199034, Russia. Institute for High Pressure Physics, Troitsk, Moscow Region 142190, Russia.
J Phys Condens Matter. 2019 Jul 3;31(26):265402. doi: 10.1088/1361-648X/ab132b. Epub 2019 Mar 25.
The phonon dispersion of FeSi was measured by inelastic x-ray scattering. The study of its temperature evolution in the range of 100 K-300 K showed that the phonon modes soften to a different extent. The phonons exhibiting specifically strong softening were revealed to belong to the weakly dispersive optical branch. At the same time, the calculations of the lattice dynamics of FeSi suggest that this branch corresponds mainly to the atomic displacements that change the Fe-Fe nearest neighbor distance. It points to the role of the Fe-Fe interaction in the phonon softening.
通过非弹性X射线散射测量了FeSi的声子色散。对其在100 K - 300 K温度范围内的温度演化研究表明，声子模式有不同程度的软化。结果显示，表现出特别强烈软化的声子属于弱色散光学支。同时，FeSi晶格动力学的计算表明，该支主要对应于改变Fe - Fe最近邻距离的原子位移。这表明Fe - Fe相互作用在声子软化中所起的作用。
