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MA: Fachverband Magnetismus
MA 7: Bulk Magnetic Materials and Magnetic Particles/Clusters
MA 7.1: Talk
Monday, March 18, 2024, 09:30–09:45, EB 407
Theoretical Investigation of the Effect of Si and Co Doping on the Physical and Magnetic Properties of Rare-Earth-Free Fe2P Magnets — •Stephan Erdmann, Halil Ibrahim Sözen, and Thorsten Klüner — Carl von Ossietzky University Oldenburg
Due to the resource criticality of rare-earth (RE) elements, there is a great interest in finding a RE-free magnet to fill in the gap between the commonly used ferrites and the Nd2Fe14B magnets. A potential candidate to fill in this gap are magnets based on the Fe2P compound, which exhibits a high magnetisation and high uniaxial anisotropy. In this work, we have performed density functional theory calculations to investigate the influence of the substitution of P and Fe by readily available elements such as Si and Co on the magnetic and physical properties of the Fe2P compound. Both elements have been chosen because they are known to increase the Curie temperature of Fe2P. For a systematic understanding, properties such as the formation energy at 0 K, as well as magnetic properties like the magnetization MS and the Curie temperature TC are screened starting from the binary structure of Fe2P. Furthermore, the combined effects of Si and Co substitution on the physical and magnetic properties are considered in quarternary (Fe,Co)2(P,Si) compounds. The TC trends of these quarternary compounds were investigated by the calculation of exchange interaction energies Jij, which revealed a positive influence of Si on the 3f-3g Fe interactions leading to an increase in TC. Co substitution leads either to an increase or decrease of the 3f-3f and 3g-3g Fe interactions and thus on TC for low and high Si contents, respectively.
Keywords: Rare-Earth-Free; Curie Temperature; Computational Material Design; Fe2P based magnets; Density-functional theory