Effect of magnetic ordering on the phonons of Co3Sn2S2: Temperature-dependent Raman study

Co${}_3$Sn${}_2$S${}_2$ is a magnetic Weyl semimetal with a magnetic phase transition at $\approx$ 170 K. Here, we report the effect of this magnetic phase transition on the lattice vibration and electron–phonon coupling of Co${}_3$Sn${}_2$S${}_2$ using temperature dependent Raman scattering in the temperature range from 7 K to 300 K. The intensities of E${}_g$ and A${}_{1g}$ phonons decrease as temperature is increased till the magnetic transition temperature (170 K) and exhibit no temperature dependence above the transition temperature. Further, the E${}_g$ phonon exhibit much stronger temperature dependence than A${}_{1g}$ phonon in the magnetic phase. The frequencies and line widths of E${}_g$ and A${}_{1g}$ modes also exhibit anomalous behavior above the magnetic transition temperature. We have used spin dependent phonon scattering model to understand these anomalies in phonon frequencies, line widths and intensities.