Konsago S.W., Žiberna K., Matavž A., Mandal B., Glinšek S., Brennecka G.L., Uršič H., Malič B.
Journal of Materials Chemistry A, vol. 13, n° 4, pp. 2911-2919, 2024
Manganese-doped 0.5Ba(Zr<sub>0.2</sub>Ti<sub>0.8</sub>)O<sub>3</sub>–0.5(Ba<sub>0.7</sub>Ca<sub>0.3</sub>)TiO<sub>3</sub> (BZT–BCT) ferroelectric thin films deposited on platinized sapphire substrates by chemical solution deposition and multistep-annealed at 850 °C, are investigated. The 100 nm and 340 nm thick films are crack-free and have columnar microstructures with average lateral grain sizes of 58 nm and 92 nm, respectively. The 340 nm thick films exhibit a relative permittivity of about 820 at 1 kHz and room temperature, about 60% higher than the thinner films, which is attributed to the dielectric grain size effect. The thinner films exhibit a larger coercive field and remanent polarization of about 110 kV cm<sup>−1</sup> and 6 mC cm<sup>−2</sup> respectively, at 1 MV cm<sup>−1</sup> compared to 45 kV cm<sup>−1</sup> and 4 mC cm<sup>−2</sup> for the thicker films. The 340 nm thick films exhibit a maximum polarization of about 47 mC cm<sup>−2</sup> at 3.5 MV cm<sup>−1</sup> and slim polarization loops, resulting in high energy storage properties with 46 J cm<sup>−3</sup> of recoverable energy storage density and 89% energy storage efficiency.
