Excellence in Research: Understanding Structural, Magnetic, and Electronic Properties of Chromium Telluride

Howard University, Washington DC

Investigators

Abstract

Non-technical Abstract In recent years, there has been an increased interest in green technologies, which can lower the dependence on non-renewable sources of energy, thus reducing their environmental impacts. Magneto-caloric materials are an important class of materials being explored in this endeavor. These materials have potential applications in solid-state refrigeration, micro-coolers, energy conversion, magnetic pump, induced magnetic hyperthermia, and controlled drug delivery. In this project, we study a room temperature magneto-caloric material, chromium telluride, to understand the relationship between its magnetic, electronic and structural properties. The research is performed at Howard University in collaboration with national laboratories, which enables Howard University researchers to forge close research collaborations with outside communities. Howard University is the largest research-active historically black university (HBCU), with a large historically underrepresented student population. Therefore, this research is bringing cutting-edge research opportunities to underrepresented minority students and is broadening their participation in materials science research. These researchers are being trained in advanced material science research, data analysis, simulations, scientific writing, and presentation skills. This will enhance their competitiveness with prospective employers both in academia and industry. Technical Abstract Recently, chromium chalcogenides have drawn much interest due to their diverse magnetic properties. This project studies one room-temperature magnetic material, chromium telluride, to understand the relation between its structural, magnetic, and electronic properties. The research includes single crystal growth, magnetic, heat capacity, magneto-transport, synchrotron x-ray scattering, and neutron diffraction studies, all supplemented by density functional theory (DFT)-based simulations. Pair distribution function studies are performed to determine the evolution of the chromium telluride structure with temperature. Coherent soft x-ray spectroscopy studies help determine its ground-state electronic structure. Furthermore, neutron diffraction studies help determine its magnetic ordering. This project helps answer unaddressed fundamental questions associated with its magneto-structural phase transitions. In addition, this material is used to explore the parallel anomalous Hall effect (PAHE). Therefore, this proposed research aligns well with the Howard Forward strategy of providing underrepresented minority students with exceptional educational and research experiences and attracting next-generation STEM scholars from such groups. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.