Research Projects

Metal germanides are an important class of refractory intermetallic with metal-metalloid covalent character in chemical bonding because of the p-block germanium resulting in high thermal and chemical stabilities. Covalently bonded high purity SiC and B4C refractory ceramics are of importance for the semiconductor technologies, protective armor and coatings. Synthesis of a material depends on the nature of the chemical bonds. The covalent nature of these materials requires high synthesis temperature to achieve high crystallinity with lower defects and high purity for important technological and strategic applications. Depending on their constituent metals, stoichiometry and crystal structure metal germanides can exhibit a range of electronic, magnetic and catalytic properties. These attributes make germanides suitable for electronics, thermoelectricity and catalysis. These properties are strongly influenced, if not improved (e.g. in catalysis), by the nanoscale. High purity covalently bonded SiC and B4C nanocrystals are of importance as a precursor for semiconductor technologies, protective coatings and composite lightweight armour. The conventional synthesis involves high temperature-long duration solid-state techniques using bulk elements as starting precursors. However, they offer poor control over composition, phase purity, particle size, while the surface is covered with organic ligands, severely compromising applications in catalysis and investigation of physical properties. Whereas the nonavailability of suitable liquid phase reaction media at high temperatures and use conventional solid-state route results in crystalline bulk SiC and B4C with typical synthesis temperature above 1300C. The study of nanostructures and structural diversity of metal-germanides, SiC and B4C then faces a synthetic bottleneck. We will target new nanomaterials by focusing on compositions currently studied mostly as bulk phases in the communities of bulk solid-state physics and chemistry, by applying innovative tools for liquid-phase nanoparticles synthesis. We will explore a new molten-salt solution-chemistry route for the synthesis of metal-germanides nanocrystals by using Na4Ge4 and GeI4 as the Ge source and investigate their properties, to the best of our knowledge the proposed work will be first time. We will also focus on covalently bonded high purity SiC and B4C nanocrystals for the semiconductor and strategic sector applications in second and third year of the project. It will strongly widen the horizon of materials studied in the nanomaterial community in general and have remarkable and very initial contribution in the area of nanoscaled metal germanides.