Pressure-induced metallization of silane.
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.
Chen
Xiao-Jia
XJ
Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA.
Struzhkin
Viktor V
VV
Song
Yang
Y
Goncharov
Alexander F
AF
Ahart
Muhtar
M
Liu
Zhenxian
Z
Mao
Ho-Kwang
HK
Hemley
Russell J
RJ
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
D008670:Metals; D012821:Silanes; D012211:Rhenium; D006859:Hydrogen; D009584:Nitrogen; D012825:Silicon