![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
Abstract
The present paper reports the effect of oxygen activity p(O2) on Nb segregation in a polycrystalline specimen of Nb doped TiO2 (2·91 at.-%). The determined segregation induced enrichment factor following annealing at 1773 K in p(O2) = 10 Pa and p(O2) = 21 kPa is 3·1 and 7·3 respectively. The data on the effect of p(O2) on the segregation induced Nb enrichment factor are considered in terms of defect disorder of Nb doped TiO2 and the related lattice charge neutrality requirements. The reported segregation data may be used for controlled modification of surface concentration gradients in TiO2 through the imposition of well defined gas phase composition during processing procedures.