title: Pressure-induced metallization of silane.
abstract: There is a great interest in electronic transitions in hydrogen-rich materials under extreme conditions. It has been recently suggested that the group IVa hydrides such as methane (CH(4)), silane (SiH(4)), and germane (GeH(4)) become metallic at far lower pressures than pure hydrogen at equivalent densities because the hydrogen is chemically compressed in group IVa hydride compounds. Here we report measurements of Raman and infrared spectra of silane under pressure. We find that SiH(4) undergoes three phase transitions before becoming opaque at 27-30 GPa. The vibrational spectra indicate the material transforms to a polymeric (framework) structure in this higher pressure range. Room-temperature infrared reflectivity data reveal that the material exhibits Drude-like metallic behavior above 60 GPa, indicating the onset of pressure-induced metallization.
authors.affiliation: Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA.
authors.forename: Xiao-Jia
authors.initials: XJ
authors.lastname: Chen
authors.forename: Viktor V
authors.initials: VV
authors.lastname: Struzhkin
authors.forename: Yang
authors.initials: Y
authors.lastname: Song
authors.forename: Alexander F
authors.initials: AF
authors.lastname: Goncharov
authors.forename: Muhtar
authors.initials: M
authors.lastname: Ahart
authors.forename: Zhenxian
authors.initials: Z
authors.lastname: Liu
authors.forename: Ho-Kwang
authors.initials: HK
authors.lastname: Mao
authors.forename: Russell J
authors.initials: RJ
authors.lastname: Hemley
mesh_terms: D001274:Atmospheric Pressure; D002621:Chemistry / Q000379:methods*; D006859:Hydrogen / Q000737:chemistry; D008670:Metals; D009584:Nitrogen / Q000737:chemistry; D011312:Pressure; D012211:Rhenium / Q000737:chemistry; D012821:Silanes / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods; D013055:Spectrophotometry, Infrared / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000379:methods; D013696:Temperature
chemical_list: D008670:Metals; D012821:Silanes; D012211:Rhenium; D006859:Hydrogen; D009584:Nitrogen; D012825:Silicon