Phase diagram of the system rhenium-boron

Thermodynamic modeling of the Re–Si–B system

“…Meschel and Kleppa [15] measured the standard enthalpy of formation of ReB 2.5 to be À21.5 AE 0.5 kJ/g$atom at 1473 AE 2 K using high-temperature direct synthesis calorimetry. They chose ReB 2.5 instead of ReB 2 because they could not get a single phase at the composition of ReB 2 , which confirmed the work of Portnoi and Romashov [13] on that the composition of ReB 2 deviates from the stoichiometric ratio. Baehren and Vollath [16] detected the standard enthalpy of formation of Re 3 B to be À32 AE 2.5 kJ/g$atom from the reaction between BN and metallic powders: xM þ yBN ¼ M x B y þ 1/2yN 2 , under different N 2 partial pressures.…”

“…Portnoi and Romashov [13,14] investigated the phase diagram of the Re-B system. They prepared the Re-B alloys from 99.4 at% B and 99.9 at% Re.…”

Rediscovering the Crystal Chemistry of Borides

“…[52] In addition single crystals of lower metal borides (diborides (MB 2 ) and monoborides (MB)) can be prepared using flux growth, with Al, Sn, and Bi most commonly used as flux reagents with powders of pure metals and boron, as in the case of AlB 2 [37] and ReB 2 ; [283] and through a mineralization reaction with iodine and pressed pellets of pure metals and boron in a sealed quartz tube at 1000 °C: CrB 4 [169] and MnB 4. [199] Reactions carried out in high-temperature furnaces and spark plasma sintering (SPS) can also be used to form metal borides, as in the case of ReB 2 , [203,208,284,382] Y 2 ReB 6 , [390] ZrB 2 and ZrB 12 , [53,129] and HfB 2.…”

Self-passivating (Re,Al)B2 coatings synthesized by magnetron sputtering

“…The films appear slightly B over-stoichiometric, potentially resulting in segregation of an amorphous B tissue phase 31 or Re sub-lattice vacancies 32 . This is not further investigated here.…”