Raman spectrum and lattice parameters of MgB2 as a function of pressure

作者：Alexander F. Goncharov, Viktor V. Struzhkin, Eugene Gregoryanz, Jingzhú Hu, Russell J. Hemley, Ho‐kwang Mao, G. Lapertot, S.L. Bud’ko, Paul C. Canfield · 发表于：Physical review. B, Condensed matter · 年份：2001 · DOI：10.1103/physrevb.64.100509 · 被引用次数：139 · 研究领域：Superconductivity in MgB2 and Alloys、Boron and Carbon Nanomaterials Research、Thermal Expansion and Ionic Conductivity

We report Raman spectra and synchrotron x-ray diffraction measurements of lattice parameters of polycrystalline ${\mathrm{MgB}}_{2}$ under hydrostatic pressure conditions up to 15 GPa. An anomalously broadened Raman band at $620{\mathrm{cm}}^{\ensuremath{-}1}$ is observed that exhibits a large linear pressure shift of its frequency. The large mode damping and Gr\"uneisen parameter indicate the vibration is highly anharmonic, broadly consistent with theoretical predictions for the ${E}_{2g}$ in-plane boron stretching mode. The results obtained may provide additional constraints on the electron-phonon coupling in the system.