A New Phase of GaN
The structural, mechanical, and electronic properties of the orthorhombic GaN (Pnma-GaN) are investigated at ambient pressure by using first-principles calculations method with the ultrasoft pseudopotential scheme. The elastic constants and phonon calculations reveal Pnma-GaN is mechanically and dyn...
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| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Wiley
2016-01-01
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| Series: | Journal of Chemistry |
| Online Access: | http://dx.doi.org/10.1155/2016/8612892 |
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| Summary: | The structural, mechanical, and electronic properties of the orthorhombic GaN (Pnma-GaN) are investigated at ambient pressure by using first-principles calculations method with the ultrasoft pseudopotential scheme. The elastic constants and phonon calculations reveal Pnma-GaN is mechanically and dynamically stable at ambient pressure. The calculated Young modulus of Pnma-GaN is 170 GPa, which is the three-fifths of wurtzite-GaN. Electronic structure study shows that Pnma-GaN is a direct semiconductor with band gap of 1.847 eV. The anisotropic calculation shows that wurtzite-GaN has a smaller elastic anisotropy than that of Pnma-GaN in Young’s modulus. In addition, when the composition of aluminum increases from 0 to 0.063 in the alloy, the band gap decreases initially and increases afterward for Pnma-Ga1−xAlxN, while, for wurtzite-Ga1−xAlxN, the band gap increases with the increasing composition x. Due to the structural porous feature, Pnma-GaN can also be expected to be a good hydrogen storage material. |
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| ISSN: | 2090-9063 2090-9071 |