Investigation of electronic, optical and mechanical properties of Ta doped LiNbO3: Ab initio calculation

In this study, electronic, optical and mechanical properties of LiNb1-xTaxO3 were investigated by ab initio (or first principle calculation) method by adding Tantalum (Ta) instead of Niobium (Nb) with 0,1 doping step from x=0 to x=1 at different concentrations. The effects of Ta additive on the electronic structure of LiNbO3 were investigated. The real and imaginary parts of the dielectric function of the LiNb1-xTaxO3 were calculated and the optical transitions between the bands were determined. Second order elastic constants of Ta doped LiNbO3 were calculated and the mechanical stability of the material was determined. In addition, using the calculated elastic constants, the Bulk modulus (B), Shear modulus (G), Young's Modulus (Y), transverse and longitudinal elastic wave velocities and Debye temperatures (ΘD) were calculated.