A Thermodynamic Estimation of the Chemical Vapor Deposition of Some Borides

Fabrication of vertically aligned single-crystalline lanthanum hexaboride nanowire arrays and investigation of their field emission

“…Recently, Zhang et al [11][12][13] and Xu et al 14 synthesized LaB 6 nanowires using BCl 3 as a boron precursor; but in the application of this method, it was difficult to obtain large-area, high-quality LaB 6 nanostructures. This difficulty might be attributed to the inherent properties of the boron precursor (that is, BCl 3 is not an effective boron precursor, 16 and strong corrosion of BCl 3 can damage the surface of the substrates and the nanowires produced at high temperatures). Brewer et al 15 reported an effective chemical vapor deposition (CVD) method to synthesize LaB 6 nanoobelisks by using LaCl 3 and B 10 H 14 as the starting materials and platinum (Pt) or gold (Au) as the catalysts.…”

Lanthanum Hexaboride Nanoobelisks

“…12,13,16 The synthesis was based on the following chemical reaction 10LaCl 3 (s) + 6B 10 H 14 (g) f 10LaB 6 (s) + 30HCl(g) + 27H 2 (g) Decaborane was used to synthesize the materials because it leads to a more thermodynamically favored reaction than boron halides used in previous syntheses of LaB 6 nanomaterials. 17 Because decaborane is solid at room temperature and can be sublimed at 70 °C, it is more convenient to handle than other gaseous or liquid boron precursors, which have much higher toxicity.…”

Intermetallic borides: structures, synthesis and applications in electrocatalysis

“…These reducing agents work at different reaction systems, thus producing borides with different crystallinities and morphologies. For instance, some boranes (e.g., B 2 H 6 , B 5 H 9 ) as volatile precursors were applied in the chemical vapor deposition (CVD) synthesis of boride nanowires, [57][58][59] while borohydrides (e.g., KBH 4 , NaBH 4 ) were widely involved in solution synthesis routes to obtain amorphous (or low crystalline) boride nanostructures. [60][61][62][63][64][65][66][67] Elemental boron or alkaline-earth borides (e.g., MgB 2 ) were available for solid phase reduction of metal sources, accompanied by the generation of boride particles.…”