Microstructure control and dielectric/piezoelectric properties of alkoxy-derived Ba(Ti,Zr)O3 thin films

Lead-free ferroelectric Ba(Ti1-x)O-3 (BTZ, x = 0.00-0.50) thin films were fabricated on Pt(111)/Ti/SiO2/Si(100) substrates by the chemical solution deposition (CSD) process using complex alkoxide solutions. When the Zr content x was increased, the crystallinity of BTZ thin films was changed from the typical random orientation to the (111) preferred orientation. From the composition dependence of the dielectric constant epsilon(r) and piezoelectric constant d(33), the pinching region at room temperature of BTZ thin films consisting of nano-crystals appeared around x = 0.20. For the BTZ thin film (x = 0.20) fabricated using an alkoxide solution with partial hydrolysis, the grain and crystallite size were increased, and the epsilon(r) and d(33) were improved to 253 and 8.9 pm/V, respectively.