Mössbauer study of pureH2Te and photodissociatedH2Te in argon

The Mössbauer spectrum of solid ${\mathrm{H}}_2$Te was observed at 4.2 K and gave a quadrupole splitting (QS) of 7.2 ± 0.2 mm/sec and an isomer shift (IS) of -0.1 ± 0.2 mm/sec relative to a Cu-${}_{}{}^{125}{}_{}{}^{}\mathrm{Sb}$ source. The Mössbauer spectrum of photodissociated ${\mathrm{H}}_2$Te in solid argon is proposed as that of Te atoms. It shows a QS of 9.2 ± 0.2 mm/sec and an IS of 0.0 ± 0.2 mm/sec relative to a Cu-${}_{}{}^{125}{}_{}{}^{}\mathrm{Sb}$ source. The IS values of ${\mathrm{Te}}^0$ were combined with those of argon matrix isolated ${}_{}{}^{125}{}_{}{}^{}\mathrm{TeCl}_4^{}{}_{}{}^{}$ (1.0 ± 0.1 mm/sec) and the results of Dirac-Fock electron-density calculations to give $\Delta 〈r^2〉=(2.8\mathrm{}\pm 0.5)\times {10}^{-3\mathrm{}}$ ${\mathrm{fm}}^2$ for the 35.5-keV level in ${}_{}{}^{125}{}_{}{}^{}\mathrm{Te}$.