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Compression behavior and phase transition of β-Si3N4 under high pressure.
- Source :
- Chinese Physics B; May2018, Vol. 27 Issue 5, p1-1, 1p
- Publication Year :
- 2018
-
Abstract
- The compressibility and pressure-induced phase transition of β-Si<subscript>3</subscript>N<subscript>4</subscript> were investigated by using an angle dispersive x-ray diffraction technique in a diamond anvil cell at room temperature. Rietveld refinements of the x-ray powder diffraction data verified that the hexagonal structure (with space group P63/m, Z = 2 formulas per unit cell) β-Si<subscript>3</subscript>N<subscript>4</subscript> remained stable under high pressure up to 37 GPa. Upon increasing pressure, β-Si<subscript>3</subscript>N<subscript>4</subscript> transformed to δ-Si<subscript>3</subscript>N<subscript>4</subscript> at about 41 GPa. The initial β-Si<subscript>3</subscript>N<subscript>4</subscript> was recovered as the pressure was released to ambient pressure, implying that the observed pressure-induced phase transformation was reversible. The pressure–volume data of β-Si<subscript>3</subscript>N<subscript>4</subscript> was fitted by the third-order Birch–Murnaghan equation of state, which yielded a bulk modulus K<subscript>0</subscript> = 273(2) GPa with its pressure derivative (fixed) and K<subscript>0</subscript> = 278(2) GPa with . Furthermore, the compressibility of the unit cell axes (a and c-axes) for the β-Si<subscript>3</subscript>N<subscript>4</subscript> demonstrated an anisotropic property with increasing pressure. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 16741056
- Volume :
- 27
- Issue :
- 5
- Database :
- Complementary Index
- Journal :
- Chinese Physics B
- Publication Type :
- Academic Journal
- Accession number :
- 129688094
- Full Text :
- https://doi.org/10.1088/1674-1056/27/5/056101