IR spectroscopy of an OH hindered rotor in ZnO

An infrared absorption band at 3326 cm$^{\mathrm{-1}}$ has been assigned to H$^{\mathrm{+}}$ in an antibonding configuration in the vicinity of another defect, perhaps Ca [1,2]. The 3326 cm$^{\mathrm{-1}}$ band has a distinctive dependence on temperature, consisting of several overlapping components whose intensities show thermally activated behavior [3] over the temperature range 4K to 50K. We have measured a series of high-resolution spectra for OH and OD to determine the energy level structure of the 3326 cm$^{\mathrm{-1}}$ center and its dependence on hydrogen isotope. The results of our analysis suggest an OH hindered rotor that is reminiscent of previous results for an off-axis OD-Li center in MgO [4]. * Permanent address: Truman State University [1] S.J. Jokela and M.D. McCluskey, Phys. Rev. B \textbf{72}, 113201 (2005). [2] M.D. McCluskey and S.J. Jokela, Physica B \textbf{401-402}, 355 (2007). [3] F. Herklotz \textit{et al.}, Phys. Rev. B \textbf{82}, 115206 (2010). [4] K. Martin \textit{et al.}, Phys. Rev. B \textbf{75}, 245211 (2007).