XPS Study of Surface Cation Segregation in Mullite/Zirconia Composites

✍ Scribed by Zhang, Zhaoming; Nowotny, Janusz; Pigram, Paul J.; Lamb, Robert N.; Nakamura, Shizuo; Yamana, Kazuo

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 606 KB
• Volume: 24
• Category: Article
• ISSN: 0142-2421
• DOI: 10.1002/(sici)1096-9918(19960916)24:9<647::aid-sia147>3.0.co;2-v

✦ Synopsis

We have investigated thermally induced cation surface segregation in mullite/zirconia composites with zirconia content ranging from 0% to 100% using x-ray photoelectron spectroscopy (XPS). As a result of thermal annealing at 1000 "C, slight surface Si enrichment with respect to A1 wasfound in the pure mullite sample (0% zirconia). In contrast to the mullite sample, surface segregation in Si, Na, A1 and Y was observed in the pure zirconia sample. The segregation behaviour of all the composite samples (10-90 mass% zirconia) is dominated by the zirconia phase. For samples with 10-100 mass% zirconia, segregation leads to the formation of silicates and sodium oxides at the surface.