Magnetism and Alloy Theory

Professor JB Staunton

[Office: PS141, Physical Sciences; email: j.b.staunton at warwick.ac.uk]

Co-Director of the Centre for Doctoral Training in Modelling of Heterogeneous Systems (HetSys)

HetSys is an EPSRC-supported Centre for Doctoral Training. It recruits enthusiastic students from across the physical sciences who enjoy using their mathematical skills and thinking flexibly to solve complex problems. By developing these skills HetSys trains people to challenge current state-of-the-art in computational modelling of heterogeneous, ‘real world’ systems across a range of research themes such as nanoscale devices, new catalysts, superalloys, smart fluids, laser-plasma interactions etc.

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.

MARMOT is a software package designed to calculate Magnetism, Anisotropy, and more, using the Relativistic Disordered Local MOment picture at finite Temperature..

Recent highlights:

Ab initio calculations of the phase behavior and subsequent magnetostriction of ${Fe}_{1 - x} {Ga}_{x}$ within the disordered local moment picture by G. A. Marchant, C. D. Woodgate, C. E. Patrick and J. B. Staunton, Phys. Rev. B103, 094414, (2021). Journal
Torque magnetometry study of the spin reorientation transition and temperature-dependent magnetocrystalline anisotropy in NdCo5 by Santosh Kumar, Christopher E. Patrick , Rachel S. Edwards, Martin R. Lees, Geetha Balakrishnan and Julie B. Staunton, J. Phys.: Condens. Matter 32, 255802, (2020) https://doi.org/10.1088/1361-648X/ab7ad6
Temperature-dependent magnetocrystalline anisotropy of rare earth/transition metal permanent magnets from first principles: The light RCo5 (R=Y, La - Gd) intermetallics by Christopher E. Patrick and Julie B. Staunton, Phys. Rev. Materials 3. 101401(R), (2019). https://doi.org/10.1103/PhysRevMaterials.3.101401
Ab initio theory of the Gibbs free energy and a hierarchy of local moment correlation functions in itinerant electron systems: The magnetism of the ${Mn}_{3} A$ materials class Phys. Rev. B 99, 144424, (2019).
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).

Some recent publications from the Magnetism and Alloy Theory Group:

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

Crystal field coefficients for yttrium analogues of rare-earth/transition-metal magnets using density-functional theory in the projector-augmented wave formalism by Christopher E. Patrick and Julie B. Staunton, J. Phys.: Condens. Matter 31, 305901 (2019) JournalLink opens in a new window, arXivLink opens in a new window, WRAPLink opens in a new window

Structural and magnetic properties of GdCo_5-xNi_xby Amy L. Tedstone, Christopher E. Patrick, Santosh Kumar, Rachel S. Edwards, Martin R. Lees, Geetha Balakrishnan and Julie B. Staunton, Phys. Rev. Materials 3, 034409 (2019) JournalLink opens in a new window, arXivLink opens in a new window, WRAPLink opens in a new window

Ab initio calculations of temperature-dependent magnetostriction of Fe and A2 Fe_1-xGa_x within the disordered local moment picture by George A. Marchant, Christopher E. Patrick and Julie B. Staunton, Phys. Rev. B 99, 054415 (2019) JournalLink opens in a new window, WRAPLink opens in a new window

First-principles calculations of the magnetocrystalline anisotropy of the prototype cell boundary phase Y(Co_1-x-y Fe_xCu_y)_{5 by}Christopher E. Patrick, Munehisa Matsumoto and Julie B. Staunton, J.Magn. Magn. Mater. 477, 147 (2019) JournalLink opens in a new window, arXivLink opens in a new window, WRAPLink opens in a new window

Ab initio theory of the Gibbs free energy and a hierarchy of local moment correlation functions in itinerant electron systems: The magnetism of the ${Mn}_{3} A$ materials class by Eduardo Mendive-Tapia and Julie B. Staunton, Phys. Rev. B 99, 144424, (2019). https://doi.org/10.1103/PhysRevB.99.144424

Temperature-dependent magnetocrystalline anisotropy of rare earth/transition metal permanent magnets from first principles: The light RCo5 (R=Y, La - Gd) intermetallics by Christopher E. Patrick and Julie B. Staunton, Phys. Rev. Materials 3. 101401(R), (2019). https://doi.org/10.1103/PhysRevMaterials.3.101401

Caloric effects around phase transitions in magnetic materials described by ab initio theory: The electronic glue and fluctuating local moments by Eduardo Mendive-Tapia and Julie B. Staunton, J. Appl. Phys. 127 (11) https://doi.org/10.1063/5.0003243

Magnetic structure of selected Gd intermetallic alloys from first principles by L. Petit, Z. Szotek, I. D,Paudyal, A. Biswas, Y. Mudryk, V. K. Pecharsky and J. B. Staunton, Phys. Rev. B 10, 014409, (2019) https://doi.org/10.1103/PhysRevB.101.014409

Tunability of the spin reorientation transitions with pressure in NdCo5 by Santosh Kumar, Christopher E. Patrick , Rachel S. Edwards, Martin R. Lees, Geetha Balakrishnan and Julie B. Staunton, Appl. Phys. Lett. 116, 102408 (2020) https://doi.org/10.1063/1.5135640

Torque magnetometry study of the spin reorientation transition and temperature-dependent magnetocrystalline anisotropy in NdCo5 by Santosh Kumar, Christopher E. Patrick , Rachel S. Edwards, Martin R. Lees, Geetha Balakrishnan and Julie B. Staunton, J. Phys.: Condens. Matter 32, 255802, (2020) https://doi.org/10.1088/1361-648X/ab7ad6

First-order ferromagnetic transitions of lanthanide local moments in divalent compounds: An itinerant electron positive feedback mechanism and Fermi surface topological change by Eduardo Mendive-Tapia, Durga Paudyal, Leon Petit and Julie B. Staunton, Phys. Rev. B 101, 174437, (2020) https://doi.org/10.1103/PhysRevB.101.174437

Spin orientation and magnetostriction of Tb(1-x)Dy(x)Fe₂ from first principles by Christopher E. Patrick, George A. Marchant, and Julie B. Staunton, Phys. Rev. Applied 14, 014091 (2020) https://link.aps.org/doi/10.1103/PhysRevApplied.14.014091Link opens in a new window

Temperature-dependent spin polarization of Heusler Co2MnSi from the disordered local-moment approach: Effects of atomic disordering and nonstoichiometry by Kenji Nawa, Ivan Kurniawan, Keisuke Masuda, Yoshio Miura, Christopher E. Patrick, and Julie B. Staunton, Phys. Rev. B 102,, 054424, (2020). https://doi.org/10.1103/PhysRevB.102.054424

Ab initio calculations of the phase behavior and subsequent magnetostriction of ${Fe}_{1 - x} {Ga}_{x}$ within the disordered local moment picture by G. A. Marchant, C. D. Woodgate, C. E. Patrick and J. B. Staunton, Phys. Rev. B103, 094414, (2021). Journal

Short period magnetization texture of B20-MnGe explained by thermally fluctuating local moments by E. Mendive-Tapia, M. dos Santos Dias, S. Grytsiuk, J. B. Staunton, S. Bluegel and S. Lounis, Phys. Rev. B103, 024410, (2021). Journal