Microwave synthesis of nanocrystalline YAlO3
Introduction YAP (YA103) doped with rare earth or transition metals demonstrate very attractive properties being a promising material as a host matrix for many applications. YAP is one of four crystalline phases occurring in the system Al2O3-Y2O3 1,2 presenting an orthorhombic perovskite structure. Other three phases in that system are a cubic garnet structure with Al-richer composition, Y3A15O12 (YAG), a monoclinic Y-richer phase, Y4A12O9 (YAM), and a metastable hexagonal phase (YAH). Solid-state reactions synthsis of YAP requires very high temperatures, above 1500 ℃7. Therefore wet chemical processes such as hydroxide coprecipitation, alkoxide- and glycothermal based routes, as well as combustion synthesis, have been used 3,4 for producing YAP as a fine powder. All these processes require a relatively long duration calcination step involving temperatures in excess of 900℃. The alkoxide approach is restricted due to the rather difficult synthesis and the limited commercial availability of various metal alkoxides. Due to the explosive character of the combustion process, the particle size cannot be controlled easily. Control over phase-pure YAP is not always achieved because the yttria alumina system exhibits several other phases. In the present work, a novel microwave assisted approach to the synthesis of single phase YAG using a citrate gel process involving nitrates of Al and Y is described.
Abdulhakim A. Almajid
Mechanical Engineering Department, King Saud University, P O Box 800,Riyadh 11421, Saudi Arabia
国际会议
The 2nd International Conference on Nanomechanics & Nanocomposites(第二届国际纳米力学与纳米复合材料会议)
北京
英文
100-103
2010-10-10（万方平台首次上网日期，不代表论文的发表时间）