Engineered Heusler Compound Heterostructures and Superlattices
Abstract
Heusler compounds are a large group of intermetallic compounds with ~1500 memberswith similar crystal structures having a vast array of tunable properties. This offers the possibilityof engineering novel materials and heterostructures possessing properties far beyond what bandgap engineering has done for III-V semiconductor technology. These properties depend on thenumber of valence electrons per formula unit allowing tuning of properties through compositionand alloying. Tuning of Heusler compound properties include semiconducting band gap,metallicity, magnetism, half-metallicity, superconductivity, shape memory, and, potentially,piezoelectricity. Combining Heusler compounds with different properties into heterostructuresand superlattices allows for fundamental studies as well as engineered applications ofmagnetoresistance and superconducting proximity effects coupled with shape memory andpiezoelectricity. Despite the wealth of tunable properties and potential for tailored dissimilarproperties heterostructures, studies of heterostructures and superlattices have not beenperformed. In this proposed study, molecular beam epitaxy and chemical beam epitaxy will beused to grow and tailor Heusler heterostructures and superlatttices combining magnetic, halfmetallic, superconducting, shape memory, topological and semiconducting Heusler compoundsto develop a fundamental scientific understanding of coupling and engineering of theirproperties. Control of composition, structure and defects is essential to gain knowledge ofintrinsic properties and their tailoring. In-situ and ex-situ atomic level structural, electronic andmagnetic characterization techniques including superconducting tunneling spectroscopy will beused to study and provide feedback control of surface, interface and bulk properties. The use ofchemical beam epitaxy is to develop a growth process that will enable a self-limiting growthcondition to improve stoichiometry control. By growing on III-V semiconductor and Perovskitecomplex oxides, the Heusler heterostructures will be coupled to materials and heterostructureswith additional multifunctional properties. The ultimate goal is to develop the new field ofmultifunctional Heusler compound heterostructures and superlattices.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 25, 2017
- Source ID
- N000141512845
Entities
People
- Chris J. Palmstrøm
Organizations
- Office of Naval Research
- United States Navy
- University of California, Santa Barbara