Structure and refractive index dispersive behavior of potassium niobate tantalate films prepared by pulsed laser deposition

► Pure perovskite phase and crack-free KTa0.5Nb0.5O3 thin films prepared by PLD. ► Slight surface roughness with a uniform densely packed microstructure. ► Relation between refractive index dispersive behavior and ABO3 structure BO6 oxygen octahedron. ► Dispersive parameter E0/S0 from single term Sellmeier oscillator approximation is 6.72 ± 0.04 × 10−14 eV m2.