Effect of deposition temperature on the microstructure, ferroelectric and mechanical properties of lead free BCZT ceramic thin films

Abstract

Thin films of 0.5[Ba0.7Ca0.3TiO3] – 0.5[Ba(Zr0.2Ti0.8)O3] (BCZT) ceramics were grown on platinized Si-substrates by pulsed laser deposition using a BCZT ceramic target. The crystal structure, morphology, ferroelectric and mechanical properties of the BCZT films were studied as a function of different deposition temperatures: 600, 650 and 700 °C. The XRD studies confirmed the crystallization of tetragonal structure for all the BCZT films and the crystallinity of these films tend to increase with increase of deposition temperature. The FESEM analysis revealed homogeneous microstructure with columnar grains, particularly at higher deposition temperature. The presence of both dark and bright ferroelectric domains with oppositely polarized states and switching behaviour is evident in the PFM images. The estimated ferroelectric polarization values and mechanical properties such as hardness and elastic modulus showed an increasing trend against deposition temperature.