Accelerated Design of Novel Heusler Compounds for Spintronics Applications

Abstract

Material discovery could be defined as the identification of a previously unexplored phases/composition which may exhibit properties that are unique or similar to that of previously explored composition. Historically, this has relied to some extent on serendipity. With the search space getting wider and at the same time an increased global competitiveness, it has become apparent that the material discovery process can be accelerated, which also helps in reducing cost. Spintronics, which utilizes both the spin and charge of an electron, is a technology that has the promise to take over existing charge-based technology. Half-metallic ferromagnets, due to their ability to generate 100% spin polarization, are considered ideal materials to be used in spintronic devices. While many candidate half-metals have been predicted based on theoretical calculations, finding a half-metallic character in experiments is still an open challenge. This provides impetus to search for new candidate materials with robust half-metallic character. In this dissertation, a new substitution scheme has been realized that allows for the design of many new functional materials in a relatively short time. It is also shown that, in many cases, alloy properties can be tuned by counting the total number of valence electrons, which is less dependent on the substitution scheme. Another approach, which paves the way to enhance the magnetic properties of the materials is also discussed. Hence with the identification of new approaches to material design, this dissertation adds value in the quest for the accelerated design of functional materials.