Formation of Cubic Silicon Nitride from the Low-Pressure Phase by High-Temperature Shock Compression
V. V. Yakushev, A. N. Zhukov, A. V. Utkin, A. I. Rogacheva, V. A. Kudakina
Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, 142432 Russia
Keywords: нитрид кремния, ударная волна, фазовые превращения, высокотемпературное ударное сжатие, уравнение состояния, сверхтвердые материалы, Silicon nitride, shock wave, phase transformations, high-temperature shock compression, equation of state, superhard materials
Abstract
The effect of high-temperature shock compression conditions on the degree of transformation of silicon nitride into a cubic gamma-modification at pressures of 36 and 50 GPa in planar recovery ampoules is studied. The x-ray Rietveld method is used to determine the quantitative phase composition before and after shock compression. The temperature reached during compression and the residual temperature after unloading are calculated. It is shown that the use of high-temperature shock compression at 36 GPa provides a higher transformation level compared to the classical approach based on the addition of copper powder into the samples.
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