The phase relations in boron have been investigated at high pressure and high temperature using a multianvil apparatus, and the quenched sample has been analyzed by x-ray diffraction, Raman spectra, and transmission electron microscopy. We demonstrate that γ-B 28 can be synthesized over a wide pressure and temperature range, and α-tetragonal B 50 (T-B 50) is obtained at higher temperatures and similar pressures. The phase boundary of the β-B 106, γ-B 28, and T-B 50 is determined at pressures between 7.0 and 18 GPa and the temperatures of 500-2200 C. The results suggest that T-B 50 might be an intermediate phase formed for kinetic reasons (Ostwald rule) on the way from β-B 106 to β-tetragonal B 192 (T-192) and γ-B 28 to T-192.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2012 Jan 17|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics