Dopant Occupancy in MgO-Codoped Lithium Niobate Crystals

摘要

On the basis of the bond valence model, the preferential occupancy of various dopant such as Mn~(2+) , Eu~(3+), Er~(3+), Nd~(3+), Lu~(3+), Yb~(3+), In~(3+), Cr~(3+), Fe~(3+) and Ti~(4+) in the ideal stoichiometric lithium niobate (SLN) crystallographic frame was investigated in a viewpoint of chemical bonds. Theoretical analysis indicates that the dopant occupancy is significantly influenced by the anti-site Nb_(Li)~(4+). Our work also shows that Mg-like ions (Mg~(2+), Zn~(2+), In~(3+), Sc~(3+)) have a repulsive effect on Nb_(Li)~(4+) ions. When removing Nb_(Li)~(4+) ion by codoping Mg-like ions, the dopant occupancy in the LN crystallographic frame is determined by the natural characteristics of dopant, which is consistent well with the result in the ideal SLN crystals.