Structure and electrical properties of (100)-oriented BiSc1/2Fe1/2O3–PbTiO3 thin films with different thickness via sol–gel method

Abstract

Structure and electric properties of the sol–gel derived 0.45BiSc1/2Fe1/2O3–0.55PbTiO3 (BFS–PT) thin films deposited on Pt(111)/Ti/SiO2/Si(100) substrates with LaNiO3 buffer layers are investigated. Highly (100)-oriented BFS–PT thin films with thickness ranging from 200 to 600 nm were synthesized by introducing LaNiO3 buffer layers. The as-deposited BFS–PT films showed enhanced dielectric and piezoelectric properties, the dielectric constant and effective piezoelectric coefficient $$d_{33}^{*}$$ was approximate 1820 and 110 pm/V respectively for film of 600 nm, which was comparable to that of BiScO3–PbTiO3 or PZT thin films. The thickness dependence of the dielectric, ferroelectric and piezoelectric properties was discussed. Besides, the direct current conduction mechanism of the films was investigated as well, indicating that bulk limited Poole–Frenkel emission was observed to dominate the leakage current in the high electric field.