Two sites of Fe³⁺in highly Mg-doped LiNBO₃

Abstract

Two species of Fe3+ ESR have been observed in LiNbO3:6% Mg codoped with 530 p.p.m. Fe. Their axial crystal field parameters, D, differ by a factor of about two. As indicated by a superposition model analysis, it is likely that the centre with the large D has to be attributed to FeLi3+, and that with the low D to FeNb3+. This assignment is also supported by recent shell model calculations of the incorporation mechanism of impurities in LiNbO3.