Heat induced phase change exchange coupled composite media (HIP-ECC)
Lead Research Organisation:
UNIVERSITY OF EXETER
Department Name: Engineering Computer Science and Maths
Abstract
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Organisations
People |
ORCID iD |
| Gino Hrkac (Principal Investigator) |
Publications
Abert C
(2014)
Spin-polarized transport in ferromagnetic multilayers: An unconditionally convergent FEM integrator.
in Computers & mathematics with applications (Oxford, England : 1987)
Barton C
(2015)
Effect of Fe under layer in ultrathin FeRh films
Barton CW
(2017)
Substrate Induced Strain Field in FeRh Epilayers Grown on Single Crystal MgO (001) Substrates.
in Scientific reports
Bryan M
(2016)
Complex spin configurations in hybrid magnetic multilayer structures due to mutual spin imprinting
in Physical Review B
Ener S
(2021)
Twins - A weak link in the magnetic hardening of ThMn12-type permanent magnets
in Acta Materialia
Hrkac G
(2015)
Magnetic vortex oscillators
in Journal of Physics D: Applied Physics
Huskisson D
(2017)
Analysis of grain size in FePt films fabricated using remote plasma deposition
in Journal of Magnetism and Magnetic Materials
Keatley P
(2017)
Imaging magnetisation dynamics in nano-contact spin-torque vortex oscillators exhibiting gyrotropic mode splitting
in Journal of Physics D: Applied Physics
Keatley P
(2016)
Direct observation of magnetization dynamics generated by nanocontact spin-torque vortex oscillators
in Physical Review B
| Description | We have developed an atomistic model system to explain the growth rate and effects of FeRh and MgO as well as developed together with collaborators in Vienna a spin polarised magnetisation dynamics model. Further more we have started the investigation of FeRh in magnetic multilayer structures with FePt and soft FeO layers. The aim is to develop a functional HIPP ECC media that can be switched at temperatures that are lower than the specific Curie temperature of the materials involved. This new magnetic hybrid material, especially FeRh, can pave the way to commercial HAMR media development. We have shown that FeRh and its first-order phase transition can open new routes for magnetic hybrid materials and devices under the assumption that it can be exploited in ultra-thin-film structures. Motivated by experimental measurements showing an unexpected increase in the phase transition temperature with decreasing thickness of FeRh on top of MgO, we develop a computational model to investigate strain effects of FeRh in such magnetic structures. Our theoretical results show that the presence of the MgO interface results in a strain that changes the magnetic configuration which drives the anomalous behavior. Further we used the MD developed here to explain optimised FePt with silver atoms based HAMR media systems in collaboration with NIMS Japan and Seagate USA. |
| Exploitation Route | The development of an atomistic model system to describe magnetic film growth on MgO. Currently this is used with collaborators in Hamburg to investigate Ultra Fast magnetisation reversal in FeRh systems. The spin diffusion model is currently used by the Vienna group of Prof Praetorius to investigate the capabilities to apply this model system to domain structures and also by HGST our industrial partner to investigate MAMR technologies. MD models developed here are in use by Toyota. |
| Sectors | Digital/Communication/Information Technologies (including Software),Energy,Manufacturing, including Industrial Biotechology,Other |
| Description | Our new MEAM potential sets developed for Rare Earth and magnetic materials have been also used in the exploration and understanding of strain stress based interfaces of magnetic/metallic and magnetic/Oxide systems. This and the associated potential development tool was applied to investigate new magnetic materials to be used in electric cars. The collaboration that was initialed with this development is the MagHem project with Toyota Motor Corporation, still ongoing. A further collaboration was initiated with Prof Matthieu Verstraete on first principle calculations of thermoelectric materials at the University of Liege, Belgium. This was used to develop an ERC proposal that was submitted in 2017. We also used the results of this project to start a new collaboration with Prof Hono at NIMS Japan on novel FePt granular systems with diameters of 4-8nm, which should have an impact on future HAMAR media systems. The latest collaboration resulted in a Scripta paper in 2017 and also in a Nature Scientific Reports paper in 2018 on FeRh and another Nature Scientific Reports in Fe/Ir/Fe multi-layers 2018. In 2020 and 2021, the new devloped potential sets have been teh basis to explain twi boundary formation in 1:12 magnetic systems. Our new developed model was published in Acta Materialia 2021 and explains the limit of occurrence of twins. |
| First Year Of Impact | 2020 |
| Sector | Digital/Communication/Information Technologies (including Software),Energy,Transport,Other |
| Impact Types | Economic |
| Description | Industrial Funding |
| Amount | € 95,000 (EUR) |
| Organisation | Toyota Motor Corporation |
| Sector | Private |
| Country | Japan |
| Start | 03/2015 |
| End | 03/2017 |
| Description | Industrial Funding |
| Amount | € 99,644 (EUR) |
| Organisation | Toyota Motor Corporation |
| Sector | Private |
| Country | Japan |
| Start | 03/2013 |
| End | 04/2015 |
| Description | Coexistence of vortex and multi-domain states: A novel magnetization phase in twisted anisotropy bilayers |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | invited talk, presented novel magnetic hybrid materials, started new collaborations with TU Vienna, and University of Glasgow Prof Stamps |
| Year(s) Of Engagement Activity | 2014 |
| Description | Control of Antiferromagnetic to Ferro-magnetic Transition of FeRh on MgO for HIP-ECC-a Thermal Switch |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | Joint Intermag/MMM San Diego, USA, January 2016, started new collaborations with Seagate and WD Hitachi in USA |
| Year(s) Of Engagement Activity | 2016 |
| Description | Interface effects on FePt (L10-phase) grains for ECC media |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | Intermag Beijing, China, May 2015, meeting with companies Toyota, Seagate and WD Hitachi, and also started new collaboration with Prof Hono at NIMS Japan |
| Year(s) Of Engagement Activity | 2015 |
| Description | Nanoscale switch for vortex polarization mediated by Bloch core formation in magnetic hybrid systems |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | International multi-disciplinary conference, Invited talk, over 100 participants from Germany, Austria, Netherlands, USA, France, UK. |
| Year(s) Of Engagement Activity | 2016 |
| URL | http://www.asc.tuwien.ac.at/~praetorius/mana2016/ |