Photoabsorption spectra of solid O₂ in ultraviolet and far-vacuum ultraviolet region at 9-30 K

We report ultraviolet and far-vacuum ultraviolet (FUV) absorption spectra of solid molecular oxygen recorded over the wavelength region 110-365 nm for temperatures between 9 and 30 K, in which the light source was dispersed from a synchrotron. The UV/FUV spectra of solids O₂ deposited at various temperatures appeared distinctly different profiles due to variation of compositions of α-O₂, β-O₂, and the imperfect crystal structure at the specific temperature; in addition, the icy sample exhibited its own scattering curve deposited at specific temperature. Resolved from the thermal ramping technique, the absorption spectra of solids α-O₂ and β-O₂ were established in the wavelength region 110-250 nm at 9 and 30 K, respectively, for the first time.