کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1621675 | 1005750 | 2010 | 4 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Retention at room temperature of the tetragonal t″-form in Sc2O3-doped ZrO2 nanopowders Retention at room temperature of the tetragonal t″-form in Sc2O3-doped ZrO2 nanopowders](/preview/png/1621675.png)
Synchrotron X-ray powder diffraction was applied to the study of the effect of crystallite size on the crystal structure of ZrO2–10 mol% Sc2O3 nanopowders synthesized by a nitrate-lysine gel-combustion route. Nanopowders with different average crystallite sizes were obtained by calcination at several temperatures, ranging from 650 to 1200 °C. The metastable t″-form of the tetragonal phase, exhibiting a cubic unit cell and tetragonal P42/nmc spatial symmetry, was retained at room temperature in fine nanocrystalline powders, completely avoiding the presence of the stable rhombohedral β phase. Differently, this phase was identified in samples calcined at high temperatures and its content increased with increasing crystallite size. The critical maximum crystallite size for the retention of the mestastable t″-form resulted of about 35 nm.
Journal: Journal of Alloys and Compounds - Volume 495, Issue 2, 16 April 2010, Pages 561–564