Regensburg 2022 – wissenschaftliches Programm

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SYUK: Symposium United Kingdom as Guest of Honor

SYUK 1: United Kingdom as Guest of Honor I

SYUK 1.5: Hauptvortrag

Mittwoch, 7. September 2022, 11:45–12:15, H2

Computational modelling of the physics of rare earth - transition metal permanent magnets from SmCo₅ to Nd₂Fe₁₄B — •Julie Staunton — University of Warwick, Coventry CV4 7AL, U.K.

Magnetic materials are ubiquitous, technologically indispensable and a deeper understanding of the physics is needed for the design of new permanent magnets. Most strong magnets contain both rare earths (RE) and transition metals (TM) and this talk will describe recently developed ab initio modelling of intrinsic properties. Each RE atom has a magnetic moment, set up by its nearly localised f-electrons, immersed in a glue of septillions of valence electrons coming from all the RE and TM atoms. Local magnetic moments associated with the TM atoms also emerge from this complex electron fluid. The magnetic properties stem from the behaviour of the RE and TM local moments, the atomic arrangements and on the overall response to applied fields. Ab initio Density Functional Theory-based Disordered Local Moment (DLM-DFT) theory provides a parameter-free, accurate account of the electrons and incorporates the effects of the fluctuating local moments by averaging over them to describe temperature dependent effects. After demonstrating the computational modelling with calculations of the light RE-Co₅ permanent magnet class, the rich and complex behaviour associated with the Fe atoms in Nd₂Fe₁₄B will be described together with its role in determining the hard magnetic properties of this champion magnet.