Thin Films Containing Heavy Group V Elements as Systems for Topological Materials

This thesis looks at growing thin films of heavy group V elements as well as using Pt to study high spin-orbit coupling for topological materials. We start with Bi/Ni bilayers that had been claimed to exhibit an usual form for superconductivity at the interface, instead we found that Bi will diffuse across the interface at room temperature over a timescale of days. The Bi would then alloy with the Ni to create the superconducting alloy NiBi3 and that elevated temperatures would accelerate this process even faster. After this we continued on to heavy half Heusler alloys, growing epitaxial thin films of YPtSb and YbPtBi on c-plane sapphire. The YPtSb thin films grew as smooth continuous layers with high quality crystallinity, but without any transport properties to point to a topological state. YbPtBi on the other hand, grew as aligned triangular islands and we observed a negative longitudinal magnetoresistance that may originate from the chiral anomaly. The chiral anomaly is an expected property of a topological Weyl semimetal. Both YPtSb and YbPtBi were matched well with the c-plane sapphire surface with induced strain and so this process could be used for other half Heusler alloys in the future.