A simple inorganic-solvent-thermal route to nanocrystalline niobium diboride

Low‐Temperature Synthesis of Nanocrystalline NbB2 Powders by Borothermal Reduction in Molten Salt

“…When the temperature increased, more NbB 2 phase was produced but there still had some impurities even at 1000°C. The results indicated that the addition of molten salt greatly decreased the synthesis temperature, which was attributed to the more homogeneous mixing and more rapid diffusion of species in the liquid state than in the solid state . According to previous researches on the mechanism of molten salt synthesis (MSS) method, the reaction rate in MSS was relied on the solubility of the reactants in the molten salt to a great extent.…”

In situ synthesis of NbB2–NbC composite powders by milling-assisted carbothermal reduction of oxide raw materials

“…Many processes are available for the fabrication of niobium boride or niobium boride-based ceramic powders including high temperature methods using solid state reactions, borothermal and carbothermal reductions [14][15][16][17][18][19][20][21], low-temperature synthesis in an autoclave [22,23], self-propagating high-temperature synthesis (SHS) [3,[24][25][26][27], chemical vapour deposition (CVD) [8] and ball milling and mechanochemical synthesis [28,29]. Borothermal and carbothermal reductions require temperatures above 1600°C to obtain the niobium boride phase if Nb 2 O 5 and B/B 2 O 3 are used as starting materials [14,15,21].…”

“…Solid state reactions were carried out using an arc furnace or RF thermal plasma starting from Nb and B elemental powders [16,17,20]. NbB 2 nanocrystals were obtained from chloride-based raw materials at low temperatures (500-600°C) using an autoclave [22,23]. SHS processes were conducted using Nb/B and Nb 2 O 5 /B powder mixtures, and non-stoichiometric phases of niobium boride were obtained instead of a single NbB 2 phase [24][25][26][27].…”

Electrochemical Synthesis of Magnesium Hexaboride by Molten Salt Technique

“…The formation of 2MgCl 2 ·3B 2 O 3 is due to the solid-state reaction between residual B 2 O 3 and MgCl 2, turn into molten state (melting point of MgCl 2 : 708°C) is confirmed by an exothermic peak at 761°C. Finally, the reactants can be oxidized thoroughly at 761°C [ 24 ]. Further weight loss observed up to 1000°C is responsible for the transformation of the reactants into desired product.…”