Integrated Ba(Sn,Ti)O₃ films for microactuator applications

Abstract

Polycrystalline thin films of Ba(Sn_0.1Ti_0.9)O₃ were deposited on pt coated silicon substrates by pulsed excimer laser ablation technique. The room temperature dielectric constant of the Ba(Sn_0.1Ti_0.9)O₃ films was 350 at a frequency of 100 kHz. The films showed a slightly diffused phase transition in the range of 275-340 K. The polarization hysteresis behavior confirmed the ferroelectric nature of the thin films. Remanent polarization (P_r) and saturation polarization (P_s) were 1.1. µ C/cm² and 3.2µ C/cm² respectively. The asymmetric capacitance-voltage curve for Ba(Sn_0.1Ti_0.9)O₃ was attributed to the difference in the nature of the electrodes. Dispersion in both the real (ε_r') and imaginary (ε_r") parts of the dielectric constant at low frequencies with increase in temperature was attributed to space charge contribution in the complex dielectric constant.