A high pressure pathway toward boron-based nanostructured solidsElectronic supplementary information (ESI) available: Experimental details, FTIR data, XPS, XRD and TEM characterization of a CaB6/CaB2O4 nanocomposite. See DOI: 10.1039/c8dt00932e

• Main Authors: Grosjean, Rémi, Le Godec, Yann, Delacroix, Simon, Gouget, Guillaume, Beaunier, Patricia, Ersen, Ovidiu, Ihiawakrim, Dris, Kurakevych, Oleksandr O, Chanéac, Corinne, Portehault, David
• Format: Journal Article
• Language: English
• Published: 12.06.2018
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c8dt00932e

Inorganic nanocomposites made of an inorganic matrix containing nanoparticle inclusions provide materials of advanced mechanical, magnetic, electrical properties and multifunctionality. The range of compounds that can be implemented in nanocomposites is still narrow and new preparation methods are required to design such advanced materials. Herein, we describe how the combination of nanocrystal synthesis in molten salts with subsequent heat treatment at a pressure in the GPa range gives access to a new family of boron-based nanocomposites. With the case studies of HfB 2 /β-HfB 2 O 5 and CaB 6 /CaB 2 O 4 ( iv ), we demonstrate by X-ray diffraction and through (scanning) transmission electron microscopy the crystallization of borate matrices into rare compounds and unique nanostructured solids, while metal boride nanocrystals remain dispersed in the matrix and maintain small sizes below 30 nm, thus demonstrating a new multidisciplinary approach toward nanoscaled heterostructures. Nanostructures under pressure. Novel boron-based inorganic nanocomposites are synthesized by transforming liquid-derived nanoparticles under extreme pressure.