Combined theoretical and experimental studies of some antiperovskite systems for energy applications

Abstract

In recent years there is a significant interest in developing and exploring new and efficient functional materials for emergent energy applications Such applications include individually tiny energy consuming device operations but necessarily implemented on a very large volume such as advanced computer chips and sensors for the Internet of Things IOT batteries for electric mobility to grid scale power handling and storage Towards this end in this work we have focused on two classes of materials namely antiperovskites and chalcogenides which are endowed with interesting set of physical properties in view of their unique structures and chemistry We have chosen two antiperovskites Fe3SnC and Co3CuN as representative cases for battery and spintronic IOT applications and the heterostructure interface between antiperovskite nitride Co3CuN and perovskite oxide LaAlO3 as an emerging hetero interface material for its diverse functionality We have combined theoretical as well as experimental work so as to generate a comprehensive understanding of the basic functionality structure chemistry property relationship of these materials and how the same unfolds in real applications in each case In the first chapter the results of the Fe3SnC system will be presented In the case of Fe3SnC the focus has been on lithiation induced changes in the magnetization and more importantly the Spin Polarization of Fe3SnC We believe that the outcome of our work on this material suggests that a new approach can be adopted in the form of Iono Spintronics leading to a spin charge battery wherein lithiation could store spin as well in addition to the charge We have performed full theoretical first principles calculations as well as detailed experiments on 1 4 Li incorporated Fe3SnC and have observed very interesting systematic which proves our hypothesis We show that lithiation induced structural strains impart changes to the band structure causing major non monotonic changes in the differential spin up and spin down density of state newline newline