Abstract
Freestanding nanocrystalline beta-Ga2O3 particles with an average grain size of 14 nm prepared by chemical method was investigated by angle-dispersive synchrotron x-ray diffraction in diamond-anvil cell up to 64.9 GPa at ambient temperature. The evolution of x-ray diffraction patterns indicated that nanocrystalline monoclinic beta-Ga2O3 underwent a phase transition to rhombohedral alpha-Ga2O3. It was found that beta- to alpha-Ga2O3 transition began at about 13.6-16.4 GPa, and extended up to 39.2 GPa. At the highest pressure used, only alpha-Ga2O3 was present, which remained after pressure release. A Birch-Murnaghan fit to the P-V data yielded a zero-pressure bulk modulus at fixed B-0(')=4: B-0=228(9) GPa and B-0=333(19) GPa for beta-Ga2O3 and alpha-Ga2O3 phases, respectively. We compared our results with bulk beta-Ga2O3, and concluded that the phase-transition pressure and bulk modulus of nanocrystalline beta-Ga2O3 are higher than those of bulk counterpart.
| Original language | English |
|---|---|
| Journal | Journal of Applied Physics |
| Volume | 107 |
| Issue number | 3 |
| Pages (from-to) | 033520 |
| ISSN | 0021-8979 |
| DOIs | |
| Publication status | Published - 2010 |
Bibliographical note
Copyright (2010) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.Keywords
- elastic moduli
- grain size
- gallium compounds
- X-ray diffraction
- nanoparticles
- high-pressure solid-state phase transformations