Epitaxial Growth and Electronic Structure of Half Heuslers Co1-xNixTiSb (001), Ni1-xCoxTiSn, and PtLuSb
Abstract
Molecular beam epitaxy has been used to successfully grow high quality single crystal films of semiconducting half-Heusler compounds on lattice matched conventional compound semiconductor heterostructures. The atomic surface reconstruction and electronic properties were studied in detail using scanning tunneling microscopy and angle resolved photoemission. For the doping levels achieved in cobalt titanium antimony, the electron mobility at room temperature was comparable to those of silicon. X-ray photoelectron spectroscopy was used to determine the electronic valence band alignment between cobalt titanium antimony and indium gallium arsenide and aluminum gallium arsenide suggesting that it may make an excellent ohmic contact to n-type materials. Controlled alloying with nickel titanium antimony allowed controlled electron doping, resulting in metallic behavior for alloy concentrations above 20%. The predicted topological compound platinum lutetium antimonide was grown on indium aluminum antimony using molecular beam epitaxy. Integrated and spin polarized angle resolved photoemission studies were used to measure a Dirac-like linear dispersing surface state with helical spin texture. The results are a direct measure of the predicted topological surface state, confirming platinum lutetium antimony to be a topological material.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 09, 2016
- Accession Number
- AD1009951
Entities
People
- Chris Palmstrom
Organizations
- University of California, Santa Barbara