We present a study of the lattice dynamical properties of $\mathrm{M}{\mathrm{n}}_{1-x}\mathrm{F}{\mathrm{e}}_x\mathrm{Si}$ with $0\le x\le 0.22$. Employing time-of-flight neutron spectroscopy and inelastic x-ray scattering, we investigate the doping dependence of phonon energies, $E_{\mathrm{ph}}$, and linewidths, ${\mathrm{\Gamma }}_{\mathrm{ph}}$. We find anomalous softening and broadening of a phonon mode propagating along the [111] direction. Ab initio lattice dynamical calculations link this softening to an enhanced electron-phonon coupling due to the doping-dependent changes of the Fermi surface. We discuss an interplay of increased electron-phonon coupling and reduced ordered magnetic moments in $\mathrm{M}{\mathrm{n}}_{1-x}\mathrm{F}{\mathrm{e}}_x\mathrm{Si}$.

中文翻译：

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Mn1−xFexSi 中的电子-声子耦合

我们对晶格动力学性质进行了研究$\mathrm{中号}{\mathrm{n}}_{1-X}\mathrm{F}{\mathrm{e}}_X硅$和$0\le X\le 0.22$。利用飞行时间中子能谱和非弹性 X 射线散射，我们研究了声子能量的掺杂依赖性，${乙}_{\mathrm{酸碱度}}$和线宽，${\mathrm{\gamma }}_{\mathrm{酸碱度}}$。我们发现沿[111]方向传播的声子模式出现异常软化和展宽。从头算晶格动力学计算将这种软化与由于费米表面的掺杂相关变化而增强的电子声子耦合联系起来。我们讨论了增加的电子声子耦合和减少的有序磁矩的相互作用$\mathrm{中号}{\mathrm{n}}_{1-X}\mathrm{F}{\mathrm{e}}_X硅$。