Strain screening by mobile oxygen vacancies in SrTiO_3

摘要

Recently, Freedman et al. [Phys. Rev. B 80, 064108 (2009)] calculated the elastic dipole tensor for several types of point defects in SrTiO_3 and showed that it is nearly traceless for oxygen vacancies. Thus, mobile oxygen vacancies are predicted to screen elastic strain fields. Here, we report detailed diffuse x-ray scattering measurements of bulk SrTiO_3 crystals prepared with controlled oxygen vacancy distributions. We verify the traceless nature of the elastic dipole tensor of an oxygen vacancy and demonstrate both correlations between oxygen vacancies and elastic strain screening by oxygen vacancies.