Seminar 8th December 2015 11 a.m. 176/2013
Atomistic modelling of industrial magnets
Dr Richard Evans
University of York
- Categories
- NGCM
- Submitter
- Susanne Ufermann Fangohr
Complex crystallographic structure of Nd2Fe14B phase permanent magnets.
Summary
Magnetic materials are essential to the operation of a plethora of technological devices, from hard disk drives to hybrid electric vehicles and wind power generators. Unlike the common magnetic elements, Fe, Co and Ni, industrial magnetic materials are engineered to tailor their properties for maximum performance. With the move towards higher density magnetic data storage and next generation hybrid cars industrial magnets are now atomically engineered, where atomic level properties determine macroscopic device performance. Future technological improvements rely on a detailed understanding of how these complex materials behave and how their properties can be further optimised. In this talk I will outline the current state-of-the-art in atomistic modelling of magnetic materials and present calculations of two industrially important magnetic materials: NdFeB permanent magnets and IrMn/CoFe bilayers for spin valve sensors. The complex nature of these alloys leads to unusual magnetic effects including a temperature induced spin reorientation transition and exchange bias caused by non-local interfacial pinned spins. Reproducing key physical features from a microscopic model is a key step towards fully predictive modelling of magnetic devices from the atom up.
Bio
Dr. Richard F L Evans is Lecturer in Condensed Matter Theory in the Physics Department at the University of York, UK. He completed his Ph.D. in Computational Physics from the University of York in 2008. He is author of 50 publications with over 1000 citations. He is lead developer of the open source VAMPIRE software package for atomistic spin model simulations. His research is focused on developing models of advanced magnetic materials and their properties including rare-earth transition metal alloys, functional magnetic oxides and disordered systems. Such materials typically exhibit exotic physical behaviour leading to complex properties both of fundamental interest and important for technological applications.