Velocity and Stability of Condensed Polymorphic SiH4: A High-Temperature High-Pressure Brillouin Investigation

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2020,（6）
• 页码范围: 48-52
• 页数: 5页
• 语种: 英文
• DOI: 10.1088/0256-307X/37/6/066201

摘要

Silane (SiH4) is a promising hydrogen-rich compound for pursing high temperature superconducting.Previous high pressure measurements of Raman,x-ray diffraction and theoretical studies on SiH4 mainly focused on its polymorphic structures above 50 GPa,while the structure and the stability under lower pressure range are still unclear.Here we report an investigation of condensed SiH4 by Brillouin scattering measurements at high temperature up to 407K and high pressure up to 18 GPa.Brillouin scattering frequencies of fluid SiH4 under compression are obtained under isothermal conditions of 300K,359K and 407K.The SiH4 becomes unstable with increasing temperature and subsequently decomposes into silicon and H2.We find that compression at room temperature induces two velocity anomalies corresponding to a fluid-solid state transition and a phase IV to phase V transition,respectively.Brillouin scattering spectra has been a powerful tool to investigate the fruitful phases and structure transitions in the hydrogen-rich compound under extreme conditions.