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Initial stages of nucleation of molybdenum and tungsten carbide phases in tungstate–molybdate–carbonate melts

“…Electrolysis products in these melts were Mo 2 C and W 2 C as confirmed by X-ray phase analysis. As shown earlier [5,7], carbide electrodes in tungstate-molybdate-carbonate melts of different composition show thermodynamically determined equilibrium electrode potentials. These results were also confirmed by a kinetic study of carbide coating electrodeposition onto solid electrodes.…”

“…Figure 8 shows the dependence of Ag electrode potential on time during the electrodeposition of Mo 2 C. It indicates that crystallization overvoltage increases with current density. According to [7], if the limiting stage is the primary formation of three-dimensional nuclei, then the following relationship should hold:…”

“…Therefore, an important role in electrolysis is played by the initial stages of crystal nucleation. The results of related investigations for electrodeposited Mo and W were presented earlier [5][6][7]. The initial stages of Mo and W carbide nucleation have not been studied so far.…”

Preparation of single phase molybdenum boride

“…For synthesis of molybdenum borides different methods have been explored such as mechanochemical [17] electrochemical [15,18], hydrothermal [1], self-propagating high-temperature syntheses (SHS) [2,19] and in situ displacement reactions [14]. Volume combustion synthesis (VCS) (also known as thermal explosion) is a synthetic method similar to the SHS.…”

Synthesis of nanocrystalline hexagonal tungsten carbide via co-reduction of tungsten hexachloride and sodium carbonate with metallic magnesium

“…More recently, other methods, such as chemical processing (carbothermal reduction of tungsten oxides or carbon-coated tungsten oxide precursors method [15]), fluid bed method, mechanical alloying, self-propagating techniques and electrochemical [16], organometallic precursor [17] and solution state methods [18], etc., have been used to prepare them. Some require high temperature and long reaction time.…”