AC electrical property studies on SrBi₂(Ta_0.5,Nb_0.5)₂O₉ thin films by excimer laser ablation

Abstract

Thin films of SrBi₂Nb₂O₉ (SBN) were grown using pulsed laser ablation. A low substrate temperature deposition was chosen to ensure good film substrate interface, and hence good ferroelectric property. A nearly polycrystalline structure was achieved after ex-situ annealing. The lower switching voltage was obtained by lowering the thickness, which did not affect the insulating nature of thefilm at all. The hysteresis results showed an excellent square shaped loop with P_r=15 μC/cm and E_c = 75 kV/cm respectively. The response of the film to external ac stimuli was studied at different temperatures, and it showed that ac conductivity values in the limiting case are in close agreement with dc values, and correspond to oxygen vacancy motion.

Key Words:

• PLD
• dielectric properties
• erroelectrics