Journal article
Compressibility of the high-pressure rocksalt phase of ZnO
We report the results of a combined experimental and theoretical investigation on the stability and the volume behavior under hydrostatic pressure of the rocksalt (B1) phase of ZnO. Synchrotron-radiation x-ray powder-diffraction data are obtained from 0 to 30 GPa. Static simulations of the ZnO B1 phase are performed using the ab initio perturbed ion method and the local and nonlocal approximations to the density-functional theory.
After the pressure induced transition from the wurtzite phase, we have found that a large fraction of the B1 high-pressure phase is retained when pressure is released. The metastability of this ZnO polymorph is confirmed through the theoretical evaluation of the Hessian eigenvalues of a nine-parameter potential energy surface.
This allows us to treat the experimental and theoretical pressure-volume data on an equal basis. In both cases, we have obtained values of the bulk modulus in the range of 160-194 GPa. For its zero-pressure first derivative, the experimental and theoretical data yield a value of 4.4+/-1.0. Overall, our results show that the ZnO B1 phase is slightly more compressible than previously reported. [S0163-1829(98)07537-7].
Language: | English |
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Year: | 1998 |
Pages: | 8949-8954 |
ISSN: | 1550235x , 24699950 , 10953795 and 01631829 |
Types: | Journal article |
DOI: | 10.1103/PhysRevB.58.8949 |