Upcoming Condensed Matter Physics Seminar

October 10, 2018

Growth and Electronic Properties of Heusler Epitaxial Thin Films
Professor Chris Palmstrom,  Electrical & Computing Engineering & Materials, UCSB
Friday, October 12, 2:00 PM, ISB 231

Heusler compounds are an exciting family of ternary intermetallics that can be composed of elements from a large fraction of the periodic table. Their electronic properties are predicted to depend on the number of valence electrons per formula unit. In general, Heusler compounds form two main variants: half-Heuslers (XYZ) with the C1b crystal structure and full-Heuslers (X2YZ) with the L21 crystal structure. They have been predicted and experimentally shown to exhibit novel electronic and magnetic properties, such as half-metallic ferromagnetism, semiconducting and superconducting. A number of half-Heusler compounds are predicted to be topological non-trivial insulators or semimetals and should display topological surface states, which would be useful for spintronic applications. The half-Heusler compounds with composition XYZ can be thought of as being a zincblende structure of XZ with the Y atoms in the octahedral sites. The close similarity to the zincblende III-V compound semiconductors and the ability to adjust the lattice parameters of III-V semiconductors by alloying over the range of lattice parameters of many Heusler compounds, makes III-V semiconductors a good choice as substrates for Heusler compound epitaxial growth. In this presentation, I will emphasize the molecular beam epitaxial growth and properties of Heusler compounds grown on III-V semiconductors. Their application in spintronic devices will also be discussed.