Thickness-dependent electrical properties of sol-gel derived Pb(Zr_(0.52)Ti_(0.48))O_3 thick films using PbTiO_3 buffer layers

摘要

Pb(Zr_(0.52)Ti_(0.48))O_3 (PZT) thick films, with thickness up to 4 μm, using PbTiO_3 (PT) buffer layers were successfully prepared on silicon-based substrates by a sol-gel method. Thermal analysis (thermogravimetric-differ-ential thermal analysis) of PT and PZT sols were used to determine the pyrolysis and annealing temperatures. X-ray diffraction results show that the PZT/PT composite thick films possess perovskite structure and the dominant crystalline orientation changes from (100) to (110) with increasing the film thickness. Furthermore, the composite thick films exhibit thickness-dependent ferroelectric and dielectric properties, i.e., the coercive field decreases while dielectric constant increases as the thickness increases. Theoretical analysis shows that the thickness-dependent electrical properties are mainly attributed to the low dielectric constant of PT buffer layer and the relaxation of internal stress in PZT films.