Epitaxial growth of BaZn_1/3Ta_2/3O_3 thin-films for microwave applications

摘要

BaZn_1/3Ta_2/3O_3(BZT) ceramics are widely used in current microwave communication applications due to the material's large-dielectric constant ( epsilon _r>25), ultra-low loss tangent (tan delta < 2x10~-5 at 2 GHz) and a near-zero temperature-coefficient of resonant frequency ( tau _f approx 0). In this paper, we report the first growth of epitaxial BZT thin films. The films are grown on MgO substrates using pulsed laser deposition. X-ray diffraction data indicate the films have a a disordered pseudocubic perovskite structure with a small tetragonal distortion (i.e. a=b= 4.100 A; c= 4.088 A). An optimized substrate temperature of 575 deg C results in films which are over 98