Dielectric properties of Ba(Zr, Ti)O3 thin films fabricated by pulsed laser deposition

Abstract

A KrF excimer laser with wavelength of 248nm and pulse width of 22ns was irradiated on rotating sintered BaZrxTi1-xO3 (BZT) (x=0.00, 0.25, 0.50, 0.75, 1.00) target at fluence of 3.0J/cm2 and pulse frequency of 2Hz. The single layer BZT films were deposited on Nb-doped SrTiO3 (111) substrate at temperature of 973K in O2-8%O3 atmospheric gas pressure of 0.1, 1 and 8Pa. The BZT super lattice films were also fabricated at same conditions of single layer BZT films. The films were oriented to (111) direction. The 2-theta peak position of BZT (111) decreased as the x value increased. In the case of x > 0.5, the dielectric constant was hardly changed by atmospheric gas pressure. The dielectric constant of the BZT solid solution film decreased as x value increases. In the case of x < 0.5, the dielectric properties were different at each atmospheric gas pressure. The temperature dependences of dielectric constant in BZT film at 100mPa and 1Pa were almost constant, however the film at 8Pa was not stable. The oxygen pressure influenced dielectric properties in particular composition region (x=0.25) where relaxor phenomenon existed.