The textural stability of yttria-doped titania membranes prepared by the sol-gel method was studied using thermal analysis, X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and N-2 physisorption techniques. In the membrane fabrication process, the hydrolysis time and geometry of the substituent group in the metal alkoxide precursor directly affected the particle size of the sol. An improvement in thermal stability was achieved in the 3 mol% yttria-doped titania membranes resulting in the retardation of the anatase-to-rutile phase transformation in the doped samples. This technology has potential application in preventing membrane cracking at high temperatures. XRD results revealed that pure and yttria-doped titanias transformed to more than 90% of rutile at temperatures higher than 600 and 800degreesC, respectively. (C) 2003 Kluwer Academic Publishers.