<title>Piezoelectric PZT thin films derived by sol-gel techniques</title>

Abstract

In this report, piezoelectric Pb(Zr_xTi_1-x)O₃ (PZT) thin films have been prepared onto platinized silicon and stainless steel substrates (SS) respectively, by using the sol-gel spin-on techniques and rapid thermal annealing (RTA) process. (i) Near 4 μm (100) oriented PZT thin films were prepared onto (111)Pt/Ti/SiO₂/Si. The dielectric constant and remnant polarization achieved 1658 and 35 μC/cm² respectively. Zr-rich PZT thin films had higher dielectric constant. The as-prepared PZT thin films were observed to have spontaneous piezoelectric responses, which was prominent in the relatively thinner films. (ii) PZT thin films were successfully deposited onto SS substrates by using a thin template of PbTiO₃ layer. The annealing temperature of PZT was decreased to 550°C. No second phase was detected to the limit of X-ray diffractmeter. The remnant polarization and piezoelectric d₃₁ constant were determined to be 35 μC/cm² and -76 pC/N, respectively. (iii) The origin of the self-poling effect was conjectured to the formation of an internal bias field in PZT thin films. The shift of Curie temperature Tc of PZT thin films was discussed on the base of two-dimensional compressive and tensile stresses introduced by different substrates.