Professor JB Staunton
[Office: PS141, Physical Sciences; Tel: +44 2476 523381, email: j.b.staunton at warwick.ac.uk]
The Magnetism and Alloy Theory Group's research aims to describe the various properties of materials via a careful account of their electronic "glue" or structure which includes spin polarisation and relativistic effects such as spin-orbit coupling. This requires HPC techniques and resources such as those available at the Centre for Scientific Computing (CSC) at the University of Warwick. The Group studies theoretical metallic magnetism in this way and also, with the same electronic basis, a theory for the types of alloys that can form when two or more metallic elements are combined. A strength of the work is that it is `first principled' so that many aspects can be tested in quantitative detail by a range of experimental measurements. The Group collaborates with several others both nationally and internationally and participates actively in the large European electronic structure PSI-K network. Ongoing projects concern the development of ab-initio electronic structure theory beyond standard DFT to include the effects of strong electron correlations and finite temperatures e.g. to rare earth and transition metal material properties. Applications are being made to rare earth-transition metal permanent magnets, spintronics, magnetic properties of heterostructures and nanoclusters, magnetocaloric and magnetic shape memory materials and also electrocaloric and thermoelectric materials.
PRETAMAG is a joint theory/experiment project exploring the physics of permanent magnets funded by EPSRC.
Here are details of a PhD project on magnetism and alloy theory associated with PRETAMAG.
- Rare-earth/transition-metal magnets at finite temperature: Self-interaction-corrected relativistic density functional theory in the disordered local moment picture, Phys. Rev. B 97, 224415 (2018).
- * A new method (FPMvB) for calculating the magnetic anisotropy of rare earth - transition metal ferrimagnets* Phys.Rev.Lett. 120, 097202, (2018).
- * Rare-earth/transition-metal magnetic interactions in R-Co5 magnets*- Phys.Rev. Materials,1, 024411, (2017).
- Theory modelling has produced a generic phase diagram of the magnetic ordering of heavy rare earth metals Phys. Rev. Lett.118, 197202 (2017).
This project brings together UK researchers with an interest in computational methods for simulations of magnetism in various systems. It embraces simulations on different length scales, starting from ab initio calculations of magnetic properties (based on the full quantum mechanical description), over atomistic modelling, representing magnetic materials by spin models, to micromagnetics, utilising finite element techniques to describe larger systems or whole devices.
Julie Staunton is also a member of the Heterogeneous Multiscale Modelling Special Interest Group at the University of Warwick which is a group of academics and research software engineers from Physics, Chemistry, Engineering, Manufacturing and Mathematics interested in modelling heterogeneous systems. This usually means simulating across multiple length and time scales, including a robust quantification of the uncertainties of the models and developing new research software.
Some recent publications from the Magnetism and Alloy Theory Group:
Fluctuating local moments, itinerant electrons, and the magnetocaloric effect: Compositional hypersensitivity of FeRh by J. B. Staunton, R. Banerjee, M. dos Santos Dias, A. Deak, and L. Szunyogh, Phys. Rev. B 89, 054427, (2014).
Metallic magnetism at finite temperatures studied by relativistic disordered moment description: Theory and application by A. Deak, E. Simon, L. Balogh, L. Szunyogh, M. dos Santos Dias, and J. B. Staunton, Phys. Rev. B 89, 224401, (2014).
Improvement of magnetic hardness at finite temperatures: Ab initio disordered local-moment approach for YCo5 by M. Matsumoto, R. Banerjee and J. B. Staunton, Phys. Rev. B 90, 054421, (2014).
Using density functional theory to describe slowly varying fluctuations at finite temperatures: local magnetic moments in Gd and the 'not so local' moments of Ni by J. B. Staunton, A. Marmodoro and A. Ernst, Journal of Physics-Condensed Matter 26, 274210, (2014).
Complex Magnetism of Lanthanide Intermetallics and the Role of their Valence Electrons: Ab Initio Theory and Experiment by
L. Petit, D. Paudyal, Y. Mudryk, K. A. Gschneidner, Jr., V. K. Pecharsky, M. Lüders, Z. Szotek, R. Banerjee, and J. B. Staunton, Phys. Rev. Lett. 115, 207201 (2015).
Statistical physics of multicomponent alloys using KKR-CPA by Suffian N. Khan, J. B. Staunton, and G. M. Stocks, Phys. Rev. B 93, 054206, (2016).
Influence of structural defects on the magnetocaloric effect in the vicinity of the first order magnetic transition in Fe50.4Rh49.6 by V. I. Zverev, A. M. Saletsky, R. R. Gimaev, A. M. Tishin, T. Miyanaga, and J. B. Staunton, Applied Physics Letters 108, 192405 (2016); doi: 10.1063/1.4949355
Verification of Anderson superexchange in MnO via magnetic pair distribution function analysis and ab initio theory by Benjamin A. Frandsen, Michela Brunelli, Katharine Page, Julie B. Staunton, and Simon J. L. Billinge, Phys. Rev. Lett. 116, 197204, (2016); doi: http://dx.doi.org/10.1103/PhysRevLett.116.197204
Short-range ordering effects on the electronic Bloch spectral function of real materials in the nonlocal coherent-potential approximation by Alberto Marmodoro, Arthur Ernst, Sergei Ostanin, Leonid Sandratskii, Paolo E. Trevisanutto, Nektarios N. Lathiotakis, and Julie B. Staunton, Phys. Rev. B 94, 224205, (2016); doi:https://doi-org/10.1103/PhysRevB.94.224205
Temperature-dependent transport properties of FeRh by S. Mankovsky, S. Polesya, K. Chadova, H. Ebert, J. B. Staunton, T. Gruenbaum, M. A. W. Schoen, C. H. Back, X. Z. Chen, and C. Song, Phys. Rev. B 95, 155139, (2017). https://doi.org/10.1103/PhysRevB.95.155139
Theory of Magnetic Ordering in the Heavy Rare Earths: Ab Initio Electronic Origin of Pair- and Four-Spin Interactions by Eduardo Mendive-Tapia and Julie B. Staunton, Phys. Rev. Lett. 118, 197202, (2017). https://doi.org/10.1103/PhysRevLett.118.197202
Frustrated magnetism and caloric effects in Mn-based antiperovskite nitrides: Ab initio theory by J. Zemen, E. Mendive-Tapia, Z. Gercsi, R. Banerjee, J. B. Staunton, and K. G. Sandeman, Phys. Rev. B 95, 184438, (2017). https://doi.org/10.1103/PhysRevB.95.184438
Rare-earth/transition-metal magnetic interactions in pristine and (Ni,Fe)-doped YCo5 and GdCo5 by Christopher E. Patrick, Santosh Kumar, Geetha Balakrishnan, Rachel S. Edwards, Martin R. Lees, Eduardo Mendive-Tapia, Leon Petit, and Julie B. Staunton, Phys. Rev. Materials 1, 024411, (2017). https://doi.org/10.1103/PhysRevMaterials.1.024411
Calculating the Magnetic Anisotropy of Rare-Earth-Transition-Metal Ferrimagnets by Christopher E. Patrick, Santosh Kumar, Geetha Balakrishnan, Rachel S. Edwards, Martin R. Lees, Leon Petit, and Julie B. Staunton, Phys. Rev. Lett. 120, 097202, (2018) https://doi.org/10.1103/PhysRevLett.120.097202
Rare-earth/transition-metal magnets at finite temperature: 'Self-interaction-corrected relativistic density functional theory in the disordered local moment picture by Christopher E. Patrick and Julie B. Staunton, Phys. Rev. B 97, 224415 (2018) https://doi.org/10.1103/PhysRevB.97.224415
Field-induced canting of magnetic moments in GdCo5 at finite temperature: first-principles calculations and high-field measurements by Christopher E. Patrick, Santosh Kumar, Kathrin Gotze, Matthew J. Pearce, John Singleton, George Rowlands, Geetha Balakrishnan, Martin R. Lees, Paul A. Goddard and Julie B. Staunton, J. Phys: Condens. Matter, 30,32lt01,(2018). https://doi.org/10.1088/1361-648x/aad029
Multisite Exchange-Enhanced Barocaloric Response in Mn3NiN by David Boldrin, Eduardo Mendive-Tapia, Jan Zemen, Julie B. Staunton, Thomas Hansen, Araceli Aznar, Josep-Lluis Tamarit, Maria Barrio, Pol Lloveras, Jiyeob Kim, Xavier Moya, and Lesley F. Cohen, Phys. Rev. X 8, 041035,(2018). https://doi.org/10.1103/PhysRevX.8.041035