Synthesis and characterization of In-Tl-Sb compounds grown by molecular beam epitaxy

The growth of TlSb and InTlSb compounds has been investigated by molecular beam epitaxy. Tl and Sb were found to produce a two phase mixture of elemen tal Sb and a Tl rich Tl7Sb2 phase. This two phase mixture was the dominant phase produced throughout a variety of substrate temperatures which ranged from 200 to 425 degrees C. Varying the V/III ratio did not affect the phase s produced but rather, only affected the amount of excess Sb found at the s urface. The composition of the Tl7Sb2 phase was determined by electron moic roprobe analysis and confirmed with x-ray diffraction (XRD). XRD also indic ated that the Tl7Sb2 phase exists in a complex multiatom per unit cell CsCl structure. Similar to the binary TlSb system, attempts to grow ternary InT lSb did not produce a single phase material. In this case a three phase mix ture of InSb, elemental Sb, and Tl7Sb2 was produced throughout a range of g rowth conditions. (C) 1999 American Vacuum Society. [S0734-2101(99)05102-7] .