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Negative thermal expansion properties in tetragonal NbPO5 from the first principles studies
- Source :
- AIP Advances, Vol 7, Iss 3, Pp 035202-035202-8 (2017)
- Publication Year :
- 2017
- Publisher :
- AIP Publishing LLC, 2017.
-
Abstract
- By using the first-principles calculations based on density functional theory combined with quasi-harmonic approximation, we have studied the geometric structural, thermal properties, and the negative thermal expansion (NTE) properties of tetrahedral NbPO5. The variations of cell parameter and cell volume of tetrahedral NbPO5 with temperature show that it displays NTE behavior in the range of 473-800 K along a-axis and the corresponding average coefficient of thermal expansion (CTE) is approximately -0.766 ×10â6 Kâ1, while the c cell parameter and the cell volume display positive thermal expansion behaviors. These results are in consistent well with the experiment observations. Further vibrational modes analysis, together with Grüneisen parameters calculations, revealed that the transverse vibration of O corner atoms accompanying the rocking motions of corner-shared NbO6 octahedron and PO4 tetrahedron dominate the negative thermal properties of tetrahedral NbPO5. Our findings will provide an understanding for the underlying mechanisms of the NTE in oxides materials.
- Subjects :
- Condensed matter physics
Chemistry
General Physics and Astronomy
02 engineering and technology
021001 nanoscience & nanotechnology
01 natural sciences
Thermal expansion
lcsh:QC1-999
Tetragonal crystal system
Octahedron
Negative thermal expansion
Ab initio quantum chemistry methods
Molecular vibration
0103 physical sciences
Tetrahedron
Density functional theory
010306 general physics
0210 nano-technology
lcsh:Physics
Subjects
Details
- Language :
- English
- ISSN :
- 21583226
- Volume :
- 7
- Issue :
- 3
- Database :
- OpenAIRE
- Journal :
- AIP Advances
- Accession number :
- edsair.doi.dedup.....cd13bd70c7a781082183d7c38e26f417