Dielectric and ferroelectric properties of (Bi₀.₅Na₀.₅)TiO₃ – (Bi₀.₅K₀.₅)TiO₃ – BaTiO₃ thin films deposited via chemical solution deposition

This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/materials-letters/.Polycrystalline ferroelectric lead-free 85 mol% (Bi₀.₅Na₀.₅)TiO₃–10 mol% (Bi₀.₅K₀.₅)TiO₃–5 mol% BaTiO₃ (85BNT–10BKT–5BT) thin films were fabricated via chemical solution deposition on platinized silicon substrates. The permittivity and dielectric loss at 1 kHz were 610 and ∼3.5%, respectively. The ferroelectric properties at room temperature and as a function of the temperature up to 125 °C were also investigated. The polarization hysteresis loop at room temperature showed a P[subscript MAX] of 31 μC/cm² and P[subscript r] of 6 μC/cm² at 200 Hz. The shapes of the hysteresis loops at room temperature and 125 °C were nearly identical, indicating good temperature stability. A dense surface morphology was observed and cross sectional microscopy revealed equiaxed grain growth. Based on these measurements, 85BNT–10BKT–5BT thin films may be a good candidate for lead-free piezoelectric-based microelectromechanical systems (MEMS)