Skip to content Skip to navigation

Abstract

AP470

Thursday, 30 May 2019 at 3:15 pm

McCullough, First Floor Auditorium, Room #115

 

Host: Ian Fisher

 

Chris Palmstrøm

University of California, Santa Barbara 

 

Growth and Electronic Properties of Heusler Epitaxial Thin Films

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.