Effects of buffer layers on the orientation and dielectric properties of Ba(Zr0.20Ti0.80)O3 thin films prepared by sol–gel method

Ba(Zr0.20Ti0.80)O3 (BZT) thin films were deposited on Pt(1 1 1)/Ti/SiO2/Si(1 0 0), LaNiO3 (LNO) and CeO2-buffered Pt(1 1 1)/Ti/SiO2/Si(1 0 0) substrates by sol–gel process. The BZT thin films directly grown on Pt(1 1 1)/Ti/SiO2/Si(1 0 0) substrates exhibited highly (1 1 1) preferred orientation, while the films deposited on Pt(1 1 1)/Ti/SiO2/Si(1 0 0) substrates with LNO and CeO2 buffer layers showed, respectively, highly (1 0 0) and (1 1 0) preferred orientation. At 1 MHz, the dielectric constants were 416, 465 and 245 for the BZT thin films grown on Pt(1 1 1)/Ti/SiO2/Si(1 0 0), LNO and CeO2-buffered Pt(1 1 1)/Ti/SiO2/Si(1 0 0) substrates, respectively. The difference in dielectric properties of these three kinds of BZT films may be attributed to the different grain sizes and various orientations.