Fabrication of highly (110)-oriented BaCeO3-based proton-conductive oxide thin films by RF magnetron sputtering method

Abstract

A proton-conductive BaCe0.9Y0.1O3−δ (BCYO) thin-film, one of the candidates for the electrolyte of intermediate-temperature solid oxide fuel cells (IT-SOFCs), was deposited on (111)Pt/TiO2/SiO2/(100)Si substrate by the RF magnetron sputtering method. The sputtering conditions, i.e., deposition temperature, pressure, and sputtering gases, were examined to improve the crystallinity of the films. The BCYO films deposited at more than 500 °C were well crystallized and showed only 110 diffraction. The addition of O2 into the sputtering gas causes adverse results of lower crystallinity and lower deposition rates. A wide-range XRD reciprocal space mapping also revealed that the (110)-oriented BCYO films can be obtained on (111)Pt/TiO2/SiO2/(100)Si substrates without the need to use any buffer layers. We consider that this BCYO film possibly shows high proton conductivity and may be a suitable material for the SOFC electrolyte because of its high crystallinity.