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Modelling finite temperature effects in rare-earth/transition-metal magnets from first principles
Date : Tuesday, November 13th, 2018 16:00 - 17:00 Place : Seminar Room 5 (A615), 6th Floor, ISSP Lecturer : Dr.Christopher E. Patrick Affiliation : University of Warwick Committee Chair : Hisazumi Akai

The unrivalled hard magnetic properties of rare-earth/transition-metal (RE-TM) compounds have  inspired decades of research aimed at understanding the physics underlying their excellent performance.  From the theoretical point of view these materials present a number of challenges, particularly to first-principles methods based on density-functional theory [1], due to (a) the complicated interplay of the itinerant d-band and highly-localized 4f electrons, (b) the ferrimagnetic nature of most RE-TM compounds and (c) the importance of temperature in realistic operating conditions.  Here I will present some of our work modelling these compounds, including use of the self-interaction correction to model the RE-4f electrons [2], the importance of including ferrimagnetic effects when comparing to experimental measurements of magnetic properties [3], and our attempts to capture the competition between RE and TM magnetic anisotropy at high temperature which can lead to spin reorientation transitions.

[1] B. L. Gyorffy et al., J.Phys. F 15, 1337, (1985)
[2] C. E. Patrick and J. B. Staunton, Phys. Rev. B 97, 224415 (2018)
[3] C. E. Patrick et al., Phys. Rev. Lett. 120, 097202 (2018); C. E. Patrick et al., J. Phys.: Condensed Matter 30, 32LT01 (2018)

*This work was performed as part of the PRETAMAG project, led by Professor J. B. Staunton. PRETAMAG is funded by the United Kingdom Engineering and Physical Sciences Research Council, grant number EP/M028941/1.

(Published on: Tuesday November 6th, 2018)