“…The negative Gibbs energy values calculated by using the Factsage package (Figure 4), 60 along with the relevant thermodynamic data and phase diagrams reported in the literature 1,6,11,23,[60][61][62][63][64][65][66][67][68][69][70] suggest that the reaction between a transition metal or rare earth metal, and elemental boron is thermodynamically favourable, at all the temperatures, which is the thermodynamic basis behind various synthesis routes, including the conventional high-temperature and high pressure arc-melting, 71,72 high temperature solid-state reaction, 73,74 as well as long time mechanical alloying. [74][75][76] Given the extremely exothermic nature of Reaction (1), 1,6,[60][61][62][63][64][65][66][67][68][69][70] the so-called self-propagating high-temperature synthesis (SHS) was also used. 77,78 These synthesis approaches suffer from various disadvantages, for example requirement of high temperature/pressure and/or long processing time and/or high agglomeration of product boride.…”