Experimental technique for the precise determination of H and D concentration in rutile (TiO2)

Abstract

Results of a precise determination of the ir absorption strength of H and D in rutile are presented, which permit determination of H or D concentration to an accuracy of 3%. The integrated absorption per ion was (2.51±0.09)×10⁻¹⁷ and (1.33±0.05)×10⁻¹⁷ cm for H and D, respectively. The procedure for calculating the H or D concentration in a particular sample from the ir absorption peaks is illustrated. Used in conjunction with the results of the theoretical analysis of the preceding paper, this technique makes possible the accurate determination of the energy and density of all electron trapping levels in TiO₂ crystals. We also describe results showing that heat treatment in a dry H₂ atmosphere at ∼800 °C results in the introduction of Ti intersititials but negligible H in the crystal, as predicted by the preceding paper. A technique for measuring diffusion parameters of H and D under conditions of strict chemical equilibrium, thus avoiding the large departures from Fick's law which usually plague such measurements in materials such as TiO₂, is also described.