Computer memory chips heat up as they shrink, and the magnetic properties that store data change with temperature in ways engineers cannot yet predict or control. This project tackles a fundamental gap in materials science: the temperature-dependent behaviour of micromagnetic parameters—specifically exchange stiffness and the Dzyaloshinskii-Moriya interaction—in ultrathin magnetic films. While saturation magnetisation and perpendicular magnetic anisotropy have reliable measurement methods, these other parameters do not. Without them, designers cannot guarantee that magnetic memory (MRAM) will work reliably at the elevated temperatures and tiny scales required by next-generation electronics. The researchers will calibrate atomistic simulations against data from carefully chosen “fruit-fly” thin films, then use that understanding to settle a disputed question: whether magnetic skyrmions—tiny whirlpool-like spin textures—move toward hot or cold ends of a temperature gradient under entropic forces. If successful, the work could improve MRAM reliability and enable ultralow-energy skyrmion-based storage, which would help meet the UK’s net-zero carbon commitments by 2050. The researchers also envisage scavenging waste heat by using temperature gradients to move data. This is fundamental science with clear engineering relevance, grounded in the practical challenge of making smaller, hotter chips work dependably.
View original technical description
This project will develop the ability to measure, predict, and control the temperature-dependent scaling of the micromagnetic parameters in ultrathin magnetic films. We shall demonstrate our control by resolving a current controversy over the temperature gradient-driven motion of skyrmions. Our efforts will be based on our prior experience with the growth of magnetic multilayers, imaging of skyrmions, and recent advances in quantitative atomistic modelling. Understanding these scalings will lead to improved designs for current magnetic memory (MRAM), which are required to perform reliably at elevated temperatures at ever smaller sizes, and can also form the basis of future skyrmion-based storage technologies that offer ultralow energy storage, essential to meet the UK net zero carbon commitments by 2050. We can even envisage using these effects to scavenge waste heat by using temperature gradients to move data. Our project will establish reliable ways to determine the temperature dependence of the difficult-to-measure micromagnetic parameters (exchange stiffness A, and Dzyaloshinskii-Moriya interaction (DMI) strength D) alongside those for which well-established methods already exist (saturation magnetisation M, perpendicular magnetic anisotropy (PMA) constant K) that determine the energy of spin textures such as skyrmions in magnetic multilayers. Data from 'fruit-fly' magnetic thin films will be used to calibrate atomistic simulations, and this combination of theory and experiment will establish the effects of heavy metal interfaces, roughness/disorder and amorphous/crystalline structure so that the nature of the scalings can be controlled. We shall use this knowledge of how to control scalings to test the idea that skyrmions move either towards hot or cold ends of a temperature gradient under entropic forces.
Plain English summaries and category classifications on this site are generated by AI and may not perfectly reflect the original research.
Is something wrong? Let us know