CsGaS2-mC64 was obtained by reaction of CsN_(3) with stoichiometric amounts of Ga_(2)S_(3) and S at elevated temperatures.The crystal structure of the air-and moisture stable compound was determined from single-crysta...CsGaS2-mC64 was obtained by reaction of CsN_(3) with stoichiometric amounts of Ga_(2)S_(3) and S at elevated temperatures.The crystal structure of the air-and moisture stable compound was determined from single-crystal X-ray diffraction data.The colourless solid crystallizes in the monoclinic space group C_(2)/c(no.15)with the lattice parameters a=10.5718(6)Å,b=10.5708(6)Å,c=16.0847(8)Å,β=99.445(4)°,V=1773.1(2)Å3,and Z=16.The compound crystallizes in the TlGaSe_(2) structure type and features anionic layers 21[Ga_(4)S_(8)^(4−)]consisting of corner-sharing Ga4S10 supertetrahedra.At temperatures above 600℃ an irreversible phase-transition to CsGaS_(2)-mC16 occurs.The phase-transition kinetics were studied using in situ high-temperature X-ray powder diffraction techniques.This transition can only be reversed by using high pressures(>5 GPa at 500℃).The compound was further characterized using Raman-and diffuse reflectance spectroscopy.Chemical bonding was analysed by DFT calculations.展开更多
文摘CsGaS2-mC64 was obtained by reaction of CsN_(3) with stoichiometric amounts of Ga_(2)S_(3) and S at elevated temperatures.The crystal structure of the air-and moisture stable compound was determined from single-crystal X-ray diffraction data.The colourless solid crystallizes in the monoclinic space group C_(2)/c(no.15)with the lattice parameters a=10.5718(6)Å,b=10.5708(6)Å,c=16.0847(8)Å,β=99.445(4)°,V=1773.1(2)Å3,and Z=16.The compound crystallizes in the TlGaSe_(2) structure type and features anionic layers 21[Ga_(4)S_(8)^(4−)]consisting of corner-sharing Ga4S10 supertetrahedra.At temperatures above 600℃ an irreversible phase-transition to CsGaS_(2)-mC16 occurs.The phase-transition kinetics were studied using in situ high-temperature X-ray powder diffraction techniques.This transition can only be reversed by using high pressures(>5 GPa at 500℃).The compound was further characterized using Raman-and diffuse reflectance spectroscopy.Chemical bonding was analysed by DFT calculations.
