Comparative study of nanocrystalline Zr_(0.85)Ce_(0.15)O_2 powders synthesised by spray-pyrolysis and gel-combustion methods

摘要

Zr_(0.85)Ce_(0.15)O_2 nanopowders synthesised by gel-combustion and spray-pyrolysis methods were comparatively studied by means of X-ray diffraction,Raman spectroscopy,thermogravimetric and differential thermal analyses,specific surface area measurements,scanning and transmission electron microscopies and chemical analysis.Fully tetragonal powders were obtained by both methods,as determined by X-ray diffraction and Raman spectroscopy.Both materials exhibited extremely small crystallite sizes (about 6 nm) and high specific surface areas (93 m~2/g and 42 m~2/g for gel-combustion and spray-pyrolysis powders,respectively).In both cases,no tetragonal-to-monoclinic transition was observed in the whole temperature range up to 1300 deg C by differential thermal analysis.The amounts of the expected impurities (Si,B,C) were acceptable and comparable in both cases.