Enhanced ferroelectric and piezoelectric properties in doped lead-free (Bi₀. ₅Na₀. ₅) ₀. ₉ ₄ Ba₀. ₀ ₆ TiO ₃ thin films

Abstract

Doping effects with respect to the electrical properties of morphotropic phase boundary (Bi₀. ₅Na₀. ₅) ₀. ₉ ₄ Ba₀. ₀ ₆ TiO ₃ thin films epitaxially grown on CaRuO ₃ electroded (LaAlO₃) ₀.₃ (Sr₂ AlTaO ₆ ) ₀.₃₅ (001) substrates were investigated. Substantial enhancement of ferroelectricity and piezoelectricity has been achieved in La+Ce codoped films with a remanent polarization P r of 29.5 μC/ cm² and a remanent piezoelectric coefficient d₃₃,[sub f] of 31 pm/V, whereas Mn doping seems more favorite to reduce the leakage current by two order of magnitude. Both doped films exhibited diodelike I-V characteristics, which are correlated with resistance switching effect.