Investigation of Surface Scaling, Optical and Microwave Dielectric Studies of Bi0.5Na0.5TiO3 thin Films

Abstract

Herein, we have investigated the optical and microwave dielectric properties of Bi 0.5 Na 0.5 TiO 3 (BNT) thin films grown under different oxygen pressure ( P O2 ) using pulsed laser deposition (PLD) technique. The X-ray diffraction measurements confirms the single phase of BNT along with secondary phase and further reduction in secondary phase and increase in BNT phase with P O2 , signifies the close relation between the crystal structure and oxygen content. The shift of Raman-active TO1, TO2 and TO3 modes towards higher wavelengths and increase in mode intensity with P O2 indicating the films degree of crystallinity. The local roughness ( α loc ) of all films obtained as ~ 0.85, and the interface width ( w ) and lateral correlation length ( ξ ) of films varies with P O2 . Also, the films exhibit the increase in refractive index and reduction in optical bandgap of due to improvement in crystallinity and reduction in the oxygen vacancies. The microwave dielectric properties show a strong P O2 depends with higher dielectric constant ( ε r = 336) with lower loss (tan δ = 0.0093) at 5 GHz which show the potential applications in high frequency devices.