Strain control of ferrimagnets

Key facts

Magnetic random access memory (MRAM) using electrical current to switch magnetic layers has been on the market for a few years. It has the potential to replace much of the memory hierarchy in computer architectures but the device footprint and energy consumption are still too large to be competitive. To address the latter, there are several ongoing investigations into the use of electric field to manipulate nanomagnets, either by directly applying a gate voltage or indirectly via piezoelectric strain. Along with this has come an interest in the physics of interfaces of magnetic layers with other materials such as ferroelectrics, oxides and topological insulators. In previous work we have pioneered the piezoelectric strain control of ultrathin ferromagnetic layers with perpendicular magnetization (relevant to perpendicular magnetic recording, for example), and we have begun to explore the influence of strain at the surface of ferroelectric barium titanate on the magnetic domain structures in adjacent ferromagnetic layers. The use of a single crystal ferroelectric enables larger strain to be generated at the interface where it is needed, in contrast to commercial piezoelectric stressors where the surfaces are too rough to deposit high quality magnetic layers. The aim of this project is to replace the ferromagnet with a ferrimagnet, which has a smaller net magnetization making it promising, for example, for fast and efficient read/write operations, and which in the right composition has a peculiar sensitivity to strain. Ferrimagnet/ferroelectric structures will be grown in the Royce deposition facility at the University of Leeds, which combines several thin film growth techniques in one system, and characterised using state-of-the-art instruments in the Condensed Matter group. The goal will be to control the magnetic properties of the ferrimagnet reversibly by applying a voltage to the ferroelectric. The choice of materials will be guided by the principle of sustainability, ensuring that they are plentiful, as defined by the European Chemical Society in 2019. This requirement is already met by the constituent elements of barium titanate and some ferrimagnets too.

To apply for this project you will need to make a formal application for research degree study through the University website. You will need to create a login ID with a username and PIN.

• For Application type please select Research Degrees – Research Postgraduate.

• The admission year for this project is 2027/28 Academic Year.

• You will need to select your Planned Course of Study from a drop-down menu. For this project, scroll down and select PHP Physics & Astronomy Full Time.

• The project start date for this project is 1 October 2027, please use this as your Proposed Start Date of Research.

• Please state clearly in the Research Information Section that the research degree you wish to be considered for is Strain control of ferrimagnets as well as Dr Thomas Moore as your proposed supervisor.

Please state clearly in the Finance section, the funding that you are applying for, if you are self-funding or externally sponsored.

More information on how to apply is available on our website here. You will be required to provide a personal statement which outlines your interest in the project you are applying for, why you have chosen it and how your skills map onto the requirements of the project.

We will assess applications continuously as we receive them. We welcome and strongly encourage any potential applicants to contact the supervisor(s) for an informal discussion, prior to applying, and recommend submitting your application early.

If you are applying with external sponsorship or you are funding your own study, please ensure you provide your supporting documents at the point you submit your application:

Full Transcripts of all degree study or if in final year of study, full transcripts to date including the grading scheme

Personal Statement outlining your interest in the project

If English is not your first language, you must provide evidence that you meet the University's minimum English language requirements (below).

As an international research-intensive university, we welcome students from all walks of life and from across the world. We foster an inclusive environment where all can flourish and prosper, and we are proud of our strong commitment to student education. Across all Faculties we are dedicated to diversifying our community and we welcome the unique contributions that individuals can bring, and particularly encourage applications from, but not limited to Black, Asian, people who belong to a minority ethnic community, people who identify as LGBT+ and people with disabilities. Applicants will always be selected based on merit and ability.

Applicants to research degree programmes should normally have at least a first class or an upper second class British Bachelors Honours degree (or equivalent) in an appropriate discipline. The criteria for entry for some research degrees may be higher, for example, several faculties, also require a Masters degree. Applicants are advised to check with the relevant School prior to making an application. Applicants who are uncertain about the requirements for a particular research degree are advised to contact the School or Graduate School prior to making an application.

The minimum English language entry requirement for research postgraduate research study is an IELTS of 6.0 overall with at least 5.5 in each component (reading, writing, listening and speaking) or equivalent. The test must be dated within two years of the start date of the course in order to be valid. Some schools and faculties have a higher requirement.

This is a non funded PhD project. Applicants are expected to be self funded or to secure external funding.

You can find out more about our Funding Opportunities on our Postgraduate Research Opportunities website.

Important: Please note that all costs associated with your arrival at Leeds (visa, Immigration Health Surcharge, flights etc) would have to be met by yourself, or you will need to find an alternative funding source.

For further information about your application, including how to apply, please contact PGR Admissions by email to epspgradmissions@leeds.ac.uk

For further information about this project, please contact Dr Thomas Moore by email to T.A.Moore@leeds.ac.uk

• Type of research degree: PhD
• Application deadline: Monday 31 May 2027
• Project start date: Friday 1 October 2027
• Country eligibility: International (open to all nationalities, including the UK)
• Funding: Non-funded
• Supervisors: Dr Thomas Moore
• Schools: School of Physics and Astronomy
• Research groups/institutes: Condensed Matter

Research areas