Hydrogen dynamics and localization in TaO0.03Ho0.01

The dynamics of hydrogen atoms in Ta-H and Ta-O-H interstitial solid solutions is analyzed. The vibrational energies of hydrogen interstitial impurity atoms are determined, and the metal-impurity interaction constants are calculated taking into account the atomic thermal vibrations in the host lattice. Hydrogen localization position in in the Ta-O-H solid solution is identified. It is found that, in the Ta-O-H solid solution, like in the Ta-H solid solution, hydrogen atoms are located in relatively undistorted tetrahedra and the distance between the hydrogen and oxygen atoms is no shorter than that in the third coordination sphere of the octahedral interstices