3.1.7. Gallium
There is no Ga–W binary phase diagram, but an absence of atmospheric-pressure binary phases is reported, and there is limited solubility As many as four Ga–S room-temperature phases have been included in the Ga–S binary phase diagram (Ga2S, GaS, Ga4S5, and GaS2), but only two (GaS and GaS2) are consistently included Work by Pardo et al. exploring that system between 50 and 66 at.% S culminated in the publication of a Ga–S phase diagram showing that Ga4S5 is not stable below 1131 K; therefore, we excluded it from our room-temperature diagram. Little work has been done to confirm the room-temperature stability of Ga2S, so it is included in the diagram, but the tie-line to it is dot-dashed to indicate this uncertainty. The thermodynamic data for the gallium sulfides is from Moiseev and Šesták [56]. The resulting Ga–S–W phase diagram, Fig. 3e, shows WS2 reacting with Ga to form binary gallium sulfides and W.