Development of Antiferromagnetic Heusler Alloys

A Study of Anisotropy in Antiferromagnets

Project details

Spintronics or spin electronics is an emerging field of applied physics which studies the intrinsic spin of an electron and its associated magnetic moment. The most successful spintronic device to date is based on the Giant Magneto Resistance effect and has been used in the read head sensor of hard disk drives for over 20 years. Until recently, most studies were based on ferromagnetic materials. In 2014 it was announced that significant spintronic phenomena occurred in metallic antiferromagnetic (AF) materials. These phenomena are an unexpected spin-Hall effect and, critically, the ability to manipulate the orientation of the AF axes using a spin polarised current pulse. This latter phenomenon is of critical importance as it has been shown that an AF material can relax 1000 times faster than a typical ferromagnetic device. Hence, in principle, an AF based storage or switching device would be capable of being many times faster than a conventional Magnetic Random Access Memory (MRAM) device which itself switches faster than a Complementary Metal-Oxide Semiconductor (CMOS) device. Such system would require significantly lower power and, importantly, any resulting orientation would not be subject to the normal demagnetising field effect that limits the performance of a device based on a ferromagnet. Because of these potential major advantages and the new physics involved in manipulating an AF material the level of worldwide research in AF materials has burgeoned. Hence this is a new emerging field of endeavour which is rapidly becoming dominant for both scientific and technological reasons. For both potential storage and switching applications the anisotropy of AF materials will be a critical parameter whose origin(s) are not yet understood.
We aim to address this via an integrated programme of ab-initio modelling and experimental measurements. The former will be undertaken via Density Functional Theory (DFT) modelling which requires no assumptions regarding, for example, crystal structure. This is important for the widely used system IrMn(x) where the AF anisotropy increases for the non-stoichiometric (x>3) composition. The experimental programme will focus on the measurement of the anisotropy. The technique to measure this property was developed by our group and is based on what is known as the exchange bias effect.

Funding agency

EPSRC (EP/V0047779/1, value: GBP 1,145,140)

Starting date

01/10/2021 (for 4 year).

Ending date

30/09/2025.
 

Development of Antiferromagnetic Heusler Alloys

Innovative and Sustainable Technologies for Reducing Critical Raw Materials dependence for Cleaner Transportation Applications (ITHACA)

Project details

To strengthen EU competiveness and gain the leadership in the efficient use of raw materials as foreseen in EU roadmaps towards 2050, it is mandatory to assess and develop substitution solutions aiming at replacing critical raw materials (CRMs) via sustainable processes, especially for those applications where CRMs play a vital role in strategic EU industrial sectors, such as aerospace and automotive industries.
Several restraining barriers must be overcome, mainly the risks of performance losses of the novel materials and the technological locks due to investments and material qualification costs which slow down the uptake to the market. The substitution readiness level (SRL) and the manufacturing readiness level (MRL) need thus to be clearly defined.
The aim of ITHACA is to bring together significant research (critical mass) expertise from all over Europe in the area of materials manufacturing and recycling in order to create a new research community able to identify and address the challenges in sustainable processes aimed at reducing CRMs in transportation applications. The creation of ITHACA Network will serve to capture and understand the current materials manufacturing scene and pump-prime activities in this area to move the sector forward.
In addition, ITHACA will draw the attention of relevant stakeholders to the potential SRL of critical elements in materials for transportation applications, obtained by sustainable and cost-effective processes at laboratory and pre-industrial scales by expert CIG members from Academia, RTOs and SMEs involved in H2020 and bilateral related projects.
The scientific focus of ITHACA will be on the assessment of processes for: i) the substitution of Yttrium (Y) in Thermal Barrier Coatings (TBCs) for aerospace engines, ii) the replacement of Cobalt (Co) alloys in components for combustion engines, and iii) the substitution of Platinum Group Metals (PGMs) in automotive catalysts.
Y, as the other Rare-Earth Elements (REEs), and PGMs are substitutable to a certain degree, but their substitution without performance losses is very challenging. Substitution of Co is also challenging and, in addition, recycling of Cobalt in alloys for engine parts is very difficult due to problems in Co separation.
The CIG will: address the substitution of Y, Co and PGMs critical elements in components which are strategic and vital for EU industries; demonstrate Y, Co and PGMs substitutability through sustainable and cost-effective processes; disseminate results among industrial stakeholders aiming at proving the MRL of Cu as PGMs substitute in automotive catalysts and the SRL of Y with mixed rare earth oxides (REOs) in TBCs and of Co alloys with intermetallics in combustion engines.

Funding agency

COST Innovators' Grant(CA15102, value: EUR 125,000)

Starting date

01/05/2020 (for 1 1.5 year).

Ending date

30/04/2021 31/10/2021 (successfully completed).
 

International Round Table on Criticality in Business Practice (IRTC-Business)

Project details

IRTC-Business continues and implements the work of IRTC, an international expert group on criticality. The project will conduct Round Tables and publish their outcomes, with the goal to apply the concepts to company use. It will support industry in assessing its exposure to criticality issues and support decision-making, as well as identifying mitigation measures. A web-based tool developed by the project will support these actions.

Funding agency

EIT RawMaterials(IRTC-Business, value: EUR 462,371)

Starting date

01/04/2020 (for 2 year).

Ending date

31/03/2022.
 

International Round Table on Materials Criticality (IRTC)

Project details

The project will establish an international round table on approaches towards assessing material criticality, taking place at established international conferences, creating synergies between different audiences such as experts in resource planning, industrial ecology, Life Cycle Assessment, and product development. The results will be published as three joint scientific papers for an expert audience and a Roadmap on Criticality for authorities.

Funding agency

EIT RawMaterials(IRTC, value: EUR 860,700)

Starting date

01/01/2018 (for 2 year).

Ending date

31/12/2019 (successfully completed).
 

Solutions for Critical Raw Materials Under Extreme Conditions (CRM-EXTREME)

Project details

Difficulties in the access to critical raw materials (CRMs) are expected to depress industrial sectors vital to Europe.

The Action focuses on the substitution of CRMs (like Cr, Co, Nb, W, Y) in high value alloys and metal-matrix composites used under extreme conditions of temperature, loading, friction, wear, corrosion, in Energy, Transportation and Machinery manufacturing industries.

The Action aims to set up a network of expertise to define the state of knowledge and gaps in multi-scale modelling, synthesis, characterization, engineering design and recycling, that could find viable alternatives to CRMs and promote the industrial exploitation of substituted materials.

The Action envisions a fully Sustainable Value Chain approach for:

  1. Machinery manufacturing industry<
  2. >
    1. Alternatives for Co and W in WC/Co cemented carbide wear resistant tool materials (Hard Metals and Cutting Tools)
    2. Alternatives for chromium- and tungsten-alloyed tool steels
  3. Energy Industry
    1. Reduction of Cr and Y in high-strength steel alloys
    2. Alternatives for Cr and other CRMs by hard, wear and corrosion resistant surface coatings
  4. Transportation Industry
  5. Alternatives for Nb in high-strength low-alloy (HSLA) steel (Automotive)
  6. Alternatives for high-temperature Ni-based superalloys (Aerospace)
A four-year Action oriented to strengthen collaboration between active researchers working in the different areas of investigation involving CRMs, is the most suitable initiative to seed the initial catalytic nucleus of growth for EU excellence in strategic CRMs substitution.

Funding agency

COST (CA15102, value: EUR 484,000)

Starting date

01/05/2016 (for 4 years).

Ending date

30/04/2020 (successfully completed).
 

Heusler Alloy Replacement for Iridium (HARFIR)

Project details

The proposed HARFIR project intends to develop antiferromagnetic (AF) Heusler alloy (HA) films to replace the antiferromagnetic alloy Iridium Manganes (IrMn), which has been widely used in all spin electronic devices including hard disk drives and next-generation magnetic memories. Accordingly the price of Ir has risen by a factor of 4 in the last five years and by more than a factor of 10 in the last decade. It is expected to soar perhaps by a factor of 100 due to its wider applications.

It is widely recognised that spin electronic technologies will displace volatile semiconductor memory technology within the next decade. Therefore the lack of availability of one crucial element from within the periodic table is a critical issue to be solved urgently.

We therefore aim to replace Ir to reduce the cost of an AF film by a factor of 10 as compared with the current IrMn. We will combine our expertise in ab initio calculations and HA film growth techniques to seek a highly anisotropic AF HA films. These films will be characterised both structurally and magnetically using synchrotron beamlines, high-resolution (scanning) transmission electron microscopy and highly sensitive electrical and magnetic measurement facilities available within the consortium. We will demonstrate a device concept with the developed AF HA films at the end of this project, showing an exchange bias greater than 1 kOe in sheet form and a blocking temperature greater than 300K.

To our knowledge we are the first group to realise the criticality of the position with regard to the supply of Ir. The developed AF HA films will be patented with the royalties shared equally among the partners in the Japan-EU consortium. The innovation within HARFIR is therefore extremely high.

Funding agency

European Commission (JST-EC DG RTD Coordinated Research Project "Development of New Materials for the Substitution of Critical Metals" (FP7-NMP-2013-EU-Japan), NMP3-SL-2013-604398, value: EUR 1,781,910)

Starting date

01/09/2013 (for 3.6 years).

Ending date

31/03/2017 (successfully completed).