Crystal Structure and Magnetism of Fe2-xPtxMnGa (x = 0, 0.2) Compounds — 97p — Alec Venner, Mason Pulse, Mohd Anas, and Parashu Kharel

Department of Chemistry, Biochemistry and Physics, South Dakota State University

Heusler compounds have been extensively investigated due to their unique magnetic and electrical transport properties. Their tunable magnetic properties with high ordering temperature and half-metallic band structure make them attractive for applications in spintronic devices. In this study, we investigate the effects of Pt doping on the magnetic and structural properties of Fe₂MnGa. Fe₂MnGa has previously been reported to have interesting structural and magnetic properties with the cubic Fe₂MnGa exhibiting room temperature antiferromagnetic order. By doping this material with Pt replacing a fraction of Fe, we are hoping that the heavy metal will give rise to new magnetic properties. Bulk samples of Fe₂MnGa and Fe_1.8Pt_0.2MnGa were prepared by arc melting in an inert argon environment. The samples were cut in half and annealed at 390 ˚C for 40 hours. Structural analysis was done by collecting x-ray diffraction patterns on a flat piece of the sample. All samples crystallized in a face centered cubic structure. A vibrating sample magnetometer was used to analyze the magnetic properties of the samples. The undoped annealed sample showed antiferromagnetic order with a Neel temperature of about 450 K and then with increasing temperature takes on a ferrimagnetic phase with a Curie temperature of about 800 K. With Pt doping, both the Neel temperature and Curie temperature decrease slightly. This study will allow us to better understand the Fe₂MnGa Heusler compound and to be able to fine tune its properties for practical applications.

This research is supported by the National Science Foundation (NSF) under Grant Numbers 2003828 and 2003856 via DMR and EPSCoR, and the department of Chemistry, Biochemistry, and Physics. Mohd Anas is supported by U.S. Department of Energy (DOE) Established Program to Stimulate Competitive Research (EPSCoR) grant no. DE-SC0024284.

South Dakota State University
Parashu Kharel