First principles calculations of Hydrogen-Titanium vacancy complexes in SrTiO3

Hydrogen has been reported to serve exclusively as a donor in many oxides, including SrTiO3. In a perfect crystal, a proton stays near an O atom, forming a strong O-H bond. In the presence of cation vacancies, i.e., Sr vacancy and Ti vacancy, protons prefer to electrically passivate the cation vacancies by forming strong bonds with the O atoms surrounding the vacancy. These result in the formation of nH-V-Sr and nH-V-Ti complexes. Based on first principles density functional calculations, local configurations and vibration signatures of nH-V-Sr complexes and their vibrational signatures have been previously reported [T-Thienprasert et al., Identification of hydrogen defects in SrTiO3 by first-principles local vibration mode calculations, Physical Review B 85, 125205 (2012)]. Here, we report the computational results for nH-V-Ti complexes and compare the results with infrared measurements reported in the literatures. (C) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.