ORALS

Modern high pressure chemistry represents a vast exciting area of research which will lead to new industrially important materials. Compared to traditional solid-state chemistry, this field is only just beginning to realize its huge potential and the image of “terra incognita” is not misused. Nowadays high pressure chemistry takes advantage of advances in X-ray diffraction. Actually, research over the last ten years has seen intensive use of in situ synchrotron radiation for direct observation of both stable and metastable synthesis pathways under extreme conditions. This strategy removes the limitations of the old ex situ ‘cook and look’ procedure. The possibility of observing synthesis in situ permits much greater precision in establishing the thermodynamic conditions needed for accessing metastable states. In this talk, I will show that the use of very high pressures and temperatures combined with the in situ probe by X-ray diffraction with synchrotron radiation is the methodological key to control the composition and microstructure (nanostructuration) of new bulk light materials (borides, carbides, Si compounds, etc.) with outstanding properties and I will give many examples from our recent studies [1-5].

References:
[1] Y. Le Godec*, A. Courac, V. Solozhenko. High-pressure synthesis of superhard and ultrahard materials. Journal of Applied Physics, American Institute of Physics, 2019, 126 (15), pp.151102.
[2] S. Pandolfi, C. Renero-Lecuna, Y. Le Godec* et al. Nature of Hexagonal Silicon Forming via High-Pressure Synthesis: Nanostructured Hexagonal 4H Polytype. Nano Letters, American Chemical Society, 2018, 18 (9), pp.5989 - 5995.
[3] R. Grosjean, Y. Le Godec*, S. Delacroix et al.. High pressures pathway toward boron−based nanostructured solids. Dalton Transactions, Royal Society of Chemistry, 2018, 47 (23), pp.7634−7639.
[4] Y. Le Godec*, M. Mezouar, D. Andrault, V. Solozhenko, O. O. Kurakevych, BORON CARBIDE AND METHOD FOR MAKING SAME, European patent 08787929.2.
[5] Y. Le Godec*, V. Solozhenko, O. O. Kurakevych, N. Dubrovinskaia, L. Dubrovinski, NANOSCALE BORON NITRIDE, US patent USPTO 2<span class="fon_main_wrapper"><span phone-source="0110230122" class="fon-phone-wrap fon-hightlighted active-call" id="fon-phone-e15G0ROojE">0110230122</span><a phone-source="0110230122" href="#" class="fonCallLinkButton active-call"><img src="data:image/png;base64,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" alt="F"/></a></span>.