Condensed phase equilibria in transition metal-Ga-Sb systems and predictions for thermally stable contacts to GaSb

Abstract

Antimonide-based compound semiconductors are promising candidates for high-frequency, low-power electronic devices as well as a variety of optoelectronic devices. To assist with the design of shallow or thermally stable contacts, we have performed thermodynamic calculations to estimate ternary phase equilibria in many of the transition metal-Ga-Sb systems. We have used the results of our calculations and a limited number of experiments to identify candidates for nonreactive elemental contacts to GaSb. Both W and Re are clearly in thermodynamic equilibrium with GaSb under the conditions considered in our study. Metal gallides and antimonides that are candidates for thermally stable contacts to GaSb are also highlighted.

Effect of reactor pressure on catalyst composition and growth of GaSb nanowires

“…The Au-Ga-Sb phases identified by XEDS for the catalyst particles of the 100 and 200 Torr nanowires fall into the pentagonal region defined by g,g 0 (Au 7 Ga 3 , Au 2 Ga, or Au 9 Ga 4 ), AuSb 2 , Sb, GaSb, and AuGa in the room-temperature Au-Ga-Sb ternary phase diagram [12]. According to the limited studies on the Au-Ga-Sb system [12,13], such ternary phases are not stable and tend to transform into thermodynamically more stable phases (binary compounds and Sb) at room-temperature. However, XEDS composition line profiles, STEM, and TEM reveal that the types I and II catalyst particles of 100 and 200 Torr nanowires are apparently homogenous Au-Ga-Sb alloys with no clear evidence of phase separation.…”

High-Entropy Intermetallics Serve Ultrastable Single-Atom Pt for Propane Dehydrogenation

“…Interestingly, the Ge-containing quaternary alloy had the PtGe-type intermetallic structure, that is, (PtCoCu)Ge (Figures S15 and S16 and Text S5), whereas the Ga-containing one showed an fcc solid-solution phase (Figures S11, S17, and S18 and Text S5). This is probably due to the large difference in Δ H f between PtGe (−90.8 kJ mol –1 ) and PtGa (−55.6 kJ mol –1 ) . As mentioned for Scheme , the significant contribution of the enthalpic term of PtGe seemed to prevail over the entropic effect to form a solid-solution phase upon multi-metallization while that of PtGa did not.…”

High-entropy intermetallics serve an ultrastable single-atom Pt for propane dehydrogenation

“…S12, S15-16, and Supplementary Text 4). This is probably due to the large difference in ΔHf between PtGe (−90.8 kJ mol −1 ) (19) and PtGa (−55.6 kJ mol −1 ) (28). As mentioned for Scheme 1, the significant contribution of the enthalpic term of PtGe seemed to prevail over the entropic effect to form a solid-solution phase upon multi-metallization, while that of PtGa did not.…”