The Equilibrium Phase Diagrams for the Tantalum-Tantalum Bromide and Tantalum-Tantalum Iodide Systems

Abstract

in the range (3-6) X 103 and appear to be characteristic of the unit TaeXy with +2 charge. Because these two bands are independent of the halide they also must be associated with transitions involving only metal orbitals within the octahedral arrangement6 of metal Inorganic Chemistry atoms. The positions of the remaining bands shift to lower energies in the order Ta6Cli22+ > Ta6Br122+ > Taeli22+. A more detailed account of the spectra, magnetic susceptibilities, and chemical properties of these ions will be given in a subsequent paper.16

The Last of the Five: the Elusive “Tantalum(III) Bromide”, a Perovskite‐Related Salt, [{Ta6}Br12]Br3[TaBr6]0.86

“…The phase diagram [10] exhibits five compounds: TaBr [11] (isostructural with Nb 6 Cl 14 and Ta 6 I 14 ) [12] and Ta 6 Br 15 [13] have been determined and are as just mentioned above, as well as the structures of TaBr 4 and TaBr 5 . The phase diagram [10] exhibits five compounds: TaBr [11] (isostructural with Nb 6 Cl 14 and Ta 6 I 14 ) [12] and Ta 6 Br 15 [13] have been determined and are as just mentioned above, as well as the structures of TaBr 4 and TaBr 5 .…”

“…[5] Elusive is the confirmation of the existence and then the crystal structure of "TaBr 3 ". [10] Single crystals of "TaBr 3 " were now obtained by reduction of TaBr 5 with the wall of the tantalum reaction container at 500°C with NaBr or RbBr as a flux. [14] The phase diagram states x = 2.83 for TaBr x with a decomposition temperature of 450 Ϯ 5°C.…”

“…[14] The phase diagram states x = 2.83 for TaBr x with a decomposition temperature of 450 Ϯ 5°C. [10] The present crystal refined to a composition of TaBr 2.94 . [15] The reaction temperature is similar to that used in equilibration experiments previously (426°C) and above the incongruent melting point of pure TaBr 2.83 .…”

Thermochemistry of the lower bromides of tantalum

“…f2) TaBr3.16 Tantalum tribromide possesses a fairly broad range of nonstoichiometry at 2 325°C which extends from TaBr,.,, to TaBr,,,, (2,9). We consider first the upper range limit.…”

“…for TaBr,: Br 68.83; found: Preparation 1, 68.81; Preparation 2, 68.79. The tetrabromide was prepared by reduction of TaBr, with aluminium foil (Ventron, 99.997%) at 250°C (2). Many attempts to prepare the compound led to material which, while exhibiting acceptable analytical purity, failed to dissolve completely and reproducibly in the calorimeter.…”