The innovation engine for new materials

Kaelin Gates

Kaelin Gates, Chemistry, Jackson State University




Jackson State University


Emily Levin

Faculty Sponsor(s): 

Ram Seshadri

Faculty Sponsor's Department(s): 

Materials Research Laboratory

Project Title: 

Varying the Lattice Parameter Mismatch of Ti1-xZrxCoSb with MnCoSb

Project Description: 

Novel magnetic phenomenon can occur when crystallographic symmetry is broken. Symmetry may be broken by adding lattice misfit strain through the incorporation of a second phase. Internal strain gradient effects on magnetic properties are an unexplored subject that can provide fundamental knowledge for magnetic intermetallics. In order to explore the effects of interfacial strain on magnetic Heusler structures, a biphasic Heusler composite was prepared by combining ferromagnetic MnCoSb with nonmagnetic Ti1-xZrxCoSb, where we can vary the lattice parameter using composition. By controlling the lattice parameter of the nonmagnetic phase, the mismatch between the two phases is changed and affects the interfacial strain. The nonmagnetic phase Ti1-xZrxCoSb (where x = 0, 0.25, 0.5, 0.75, 1.0) was arc melted and then annealed at several temperatures. The lattice parameter changes by replacing the smaller Ti with the larger isoelectronic Zr. Rietveld refinement of X-ray diffraction shows a single phase for heat treatments over 800°C, and increasing lattice parameter with increasing x. The heat treatment found to provide a solid solution between TiCoSb and ZrCoSb will be used to anneal the composite with MnCoSb such that the magnetic phase is separated from the Ti1-xZrxCoSb solid solution. Further characterization will be done by scanning electron microscopy (SEM). We hope to learn how the varied lattice mismatch affects interfacial strain and also how that affects magnetic properties