Computer simulation of metal co-doping in lithium niobate

Lithium niobate, LiNbO3, is an important technological material with good electro-optic, acousto-optic, elasto-optic, piezoelectric and nonlinear properties. Computer modelling provides a useful means of determining the properties of the material, including its defect chemistry, and the effect of doping on the structure. In this work, double-doped LiNbO3 was studied, and the energetics of the solid-state reactions leading to incorporation of the dopants was calculated. The following combinations of dopants were studied: Fe and Cu; Ce and Cu; Ce and Mn; Fe and Rh; and Ru and Fe. For most of these combinations, the co-doping process decreases the energy required for incorporation of the dopants, and the final defect configurations are consistent with experimental results, where available.