Enthalpies of formation of rare-earth borides from first principles. Comparison with experimental values

Ab initio thermodynamic properties of certain compounds in Nd-Fe-B system

“…However, the computed values are not able to reflect this difference in enthalpy. The similar results have been obtained in the recent DFT calculations for the Nd-B binary system by Colinet and Tedenac [4], as well as for isostructural Gd 2 B 5 investigated in the same work. This discrepancy between experimental and DFT results suggests a characteristic of the R 2 B 5 structure which is not being captured by either GGA or GGA+U calculations.…”

“…Li et al [3] have reported ab initio thermodynamic properties of several borides relevant to the Fe-B system. Recently, another ab initio investigation [4] reported enthalpies of formation of Nd-B compounds using GGA functionals.…”

Low temperature controllable synthesis of transition metal and rare earth borides mediated by molten salt

“…Typical properties of some rare earth hexaborides. [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] Boride Density/g cm −3 In the case of 'template-growth' mechanism dominated MSS, the reactant with a much higher solubility dissolves preferentially in the molten salt. The dissolved reactant species arrive at the surface of the much less-soluble reactant via rapid diffusion through the molten salt medium, and subsequently react with the latter to form an in-situ product phase.…”

“…[22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] A unique combination of these excellent properties enables REHBs to find applications in many important areas, for example field electron cathode, electrical coating for resistor, decorative coating on wristwatch and eyeglass frame, thermionic emissionbased solar energy harnessing, sensor in high-energy optical device, energy saving window and photothermal therapy. [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] As well as their excellent bulk properties mentioned above, many transition metal and rare earth borides in the powdered form, show some other good properties, in particular, high catalytic activity and adsorption capacity, making them very useful for catalysis of several novel reaction processes, for example hydrogen generation from ammonia-borane or borohydride hydrolysis, or water-splitting, and for high efficiency waste-water treatment. [39][40][41][42][43][44][45]…”

“…There exist a multitude of metal borides among which transition metal diborides (TMDBs) and rare earth hexaborides (REHBs) have been subjected to the most extensive investigations owing to their unique structures, superior properties, and great potential for diverse applications. 1–46 The former possesses a simple AlB 2 -type crystal structure with a space group of P6/mmm in which the hexagonal close-packed metal layers alternate with the boron (B) layers (Figure 1(a)), 20 and the latter possesses a CsCl-type structure with a space group of Pm-3m in which the rare earth metal atoms and the B atoms occupy respectively the Cs sites and the octahedral sites, and one B 6 octahedron is surrounded by eight rare earth metal atoms (Figure 1(b)). 22 Among the 17 existing rare-earth metal elements, however, only 13 form stable corresponding hexaborides, that is RB 6 (R = Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er and Yb) 22 (LuB 6 and TmB 6 can be formed as metastable phases).…”