Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1620666 | Journal of Alloys and Compounds | 2010 | 6 Pages |
Abstract
Pyrochlore powders Gd2(Ti0.65Zr0.35)2O7, were synthesized by mechanical milling of constituent oxides, and their grain-sizes (from <20 nm to μm-sized) were controlled by subsequent thermal treatments (800-1500 °C). Using in situ X-ray diffraction (XRD) measurements at pressures up to more than 40 GPa, the bulk moduli were determined to be greater (>10%) than the values of the end-member compositions: Gd2Ti2O7 and Gd2Zr2O7. The higher values are attributed to the mixed occupancy of cations at the A- and B-sites. There was also a significant increase in the stability of Gd2(Ti0.65Zr0.35)2O7 as the grain-size decreased below a critical value. The nanocrystalline sample, <20 nm, had a transition to the high-pressure phase that was â¼10 GPa higher than that for the same composition but with grain-size larger than 100 nm.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
F.X. Zhang, J. Lian, J.M. Zhang, K.J. Moreno, A.F. Fuentes, Zhongwu Wang, R.C. Ewing,