Research Spotlights

By Georgia Barrington-Smith

Amidst the ongoing global energy crisis, industries such as power, manufacturing, and transportation are significant contributors to energy consumption. These sectors produce substantial amounts of unwanted heat as a byproduct, typically released into the environment through exhaust systems, heated surfaces, or cooling mechanisms. This thermal energy, often considered waste, represents a largely underutilised resource.

Fortunately, innovative technologies are emerging to capture and transform this excess heat into usable energy. By harnessing this thermal energy, industries can reduce their overall energy consumption and hence lower their consumption of fossil fuels.

Advancing energy efficiency through breakthrough materials

Thermoelectric materials are a promising technology for capturing this wasted heat. These materials convert heat into electrical energy through the Seebeck effect, in which temperature differences cause the movement of charge carriers.

Recent advancements have shown that incorporating magnetic nanoparticles into these thermoelectric materials can significantly enhance their performance and energy efficiency.

Kyle Portwin, an AINSE PGRA scholar, along with collaborators at ANSTO and the University of Wollongong, has investigated the interactions between magnetic nanoparticles and tin selenide, a promising thermoelectric material, to assist in the development of higher performing energy-efficient materials.

Inside magnetic thermoelectric materials

Magnetic thermoelectric materials are highly complex systems due to the interplay of three types of (quasi)particles:

• Electrons, which carry electric charge,
• Phonons, the vibrations of the atomic lattice that transport heat, and
• Magnons, related to the spin structure of electrons.

Electrons interact with both phonons and magnons, while phonons and magnons can also influence each other independently. Understanding these interactions is crucial for designing advanced thermoelectric materials with enhanced energy efficiency.

To study these interactions, Kyle used inelastic neutron scattering (INS) techniques at ANSTO’s Australian Centre for Neutron Scattering (ACNS) facility, and computational techniques such as density functional theory (DFT), molecular dynamics and linear spin wave theory, to model the dynamics of electrons, atoms and spins in materials.

Specifically, Kyle used Time-of-Flight inelastic neutron scattering, a technique that allows the observer to “see” how particles like phonons and magnons behave inside a material, providing information about its thermoelectric performance.

Using this technique, Kyle was able to analyse some key properties of thermoelectric materials, including quasiparticle broadening (the spread of particle energy), softening (a reduction in energy), and group velocity (the speed at which disturbances travel through the material), to gain deeper insights into the microscopic interactions that govern thermoelectric efficiency.

Why are these properties important?

Understanding thermoelectric materials using inelastic neutron scattering

Kyle focused his research on one particular thermoelectric material: tin selenide (SnSe), known for its exceptional thermoelectric performance due to its ultralow thermal conductivity, and moderate electrical conductivity.

Using Time-of-Flight INS and DFT calculations, Kyle investigated how SnSe behaves when heated from 100 K – 500 K. The analysis revealed significant broadening of phonon modes, where the vibrations within the material become less well-defined. Normally, phonons have a sharp, clear energy signature, similar to a well-tuned musical note. However, broadening causes this energy range to become fuzzy, like a musical note that’s blurred by nearby vibrations, losing its sharpness and clarity. Additionally, a softening effect was observed where phonon modes shifted to lower energies. This indicating that atomic bonds had become weaker, and the system’s vibrations more anharmonic.  

As optical modes broadened and softened to lower energies, the acoustic modes became confined to a smaller region of phase space. This caused the vibrations in the material to lose energy and spread out, leading to a decrease in phonon group velocity. Consequently, the speed at which heat travels through the material slowed down. Since these vibrations typically carry heat, their limited movement reduces heat conduction through SnSe, greatly improving thermoelectric performance.

Using magnetic nanoparticles to boost thermoelectric materials

Magnetite (Fe₃O₄) nanoparticles are promising candidates for integration with thermoelectric materials because they are strongly magnetic (high magnetic moment), retain their magnetism well (high coercivity), and remain magnetic even at elevated temperatures (high Curie temperature)—a crucial feature for thermal energy applications.

When these nanoparticles become sufficiently small, they enter a special state called superparamagnetism, where each tiny particle acts like a miniature magnet that can easily flip its direction. This unique behaviour can influence how heat and electricity move through a material, potentially improving its energy performance.

To explore how magnetic nanoparticles affect thermoelectric materials, Kyle embedded Fe₃O₄ nanoparticles into a SnSe matrix. Using Time-of-Flight INS, he discovered that the vibrations in the SnSe became significantly broader—especially at higher energy levels—when combined with Fe₃O₄. This effect went beyond a simple combination of the two materials’ behaviours, indicating the possible formation of new, hybrid phonon-magnon modes inside the composite material.

These hybrid modes may influence both electrical conductivity and thermal transport by introducing new pathways for energy transfer, an area that will be further explored in the final stages of Kyle’s PhD research.

Kyle’s research lights the way for next-gen energy conversion technologies

By merging magnetism with thermoelectric materials, Kyle’s research points to a bold new direction for turning waste heat into usable energy.

Kyle’s ongoing research into the interactions of electrons, phonons, and magnons seeks to inform the development of advanced materials for improved energy conversion and long-term sustainability. Such advancements have important applications in sustainable power generation and electronic cooling.

AINSE are proud to spotlight Kyle for his pioneering work!

If you, like Kyle, want to become part of the next generation of researchers addressing global energy challenges, learn how AINSE scholarships can support your research journey at ainse.edu.au/scholarships.

To keep exploring AINSE’s research spotlights head to ainse.edu.au/research-spotlights/.

As we end Magnetic May charged up on curiosity, we transition into a new month exploring the wonders of space for Lunar June!

Keep connected as we share our first spotlight showcasing the fascinating work of Larissa Lopes Cavalcante, an AINSE PGRA scholar, examining the chemical complexity of Titan, Saturn’s largest moon!

Follow ainse_ltd on Instagram, Facebook, Threads and LinkedIn to keep up to date with upcoming events and research spotlights.

By Georgia Barrington-Smith

In today’s digital era, the rapid proliferation of online services and cloud computing has driven an unprecedented global demand for data centres. These facilities support the storage and distribution of vast data volumes, ranging from AI models to high-demand streaming content.

Unfortunately, as our reliance on digital infrastructure and artificial intelligence accelerates, so too does its environmental footprint. Data centres, despite their benefits, consume vast amounts of energy to run. By 2040, the growing demand for energy by digital data storage alone could account for up to 14% of global carbon emissions.

Meeting this rising demand without overwhelming the planet’s resources requires bold innovation—starting at the very foundation of computing: the microscopic materials that drive our devices.

Beyond the limits of silicon

At the heart of modern electronics are semiconductors, tiny components that enable the function of everything from smartphones to supercomputers. Silicon-based semiconductors have been widely used for years, but their low energy efficiency and susceptibility to electrical leaks can limit their performance as demand continues to grow for smaller, faster, and more powerful devices.

It is becoming apparent that we are nearing the limits of what can be achieved with silicon-based technology. To meet global data demands, researchers are now seeking new materials capable of delivering more performance capabilities with less energy required.

Enter spintronics: A quantum leap forward

One such breakthrough is emerging in the field of spintronics (spin electronics). Unlike conventional devices that rely solely on the flow of electrical charge, spintronic technology also harnesses the spin of electrons, a quantum property that gives them magnetic potential.

By encoding binary data using spin states, commonly referred to as “up” or “down”, spintronic devices offer the promise of faster processing speeds, higher data storage density, and significantly lower energy consumption. These advances position spintronics as a leading candidate for powering the next generation of sustainable electronics.

Marco makes magnetic vortexes

Marco Vás, an AINSE PGRA scholar, is contributing to this transformation through his work with ANSTO and the University of Auckland. His research focuses on material optimisation to be better used in developing spintronic devices that are not only faster and more efficient than traditional semiconductors, but also capable of scaling sustainably with digital demand.

While spintronic components are already in use in some modern technologies, Marco is pushing the boundaries further with a novel data storage technique known as skyrmion racetrack memory.

Skyrmions are stable, vortex-like quasiparticles formed by the interaction of atomic magnetic moments under specific conditions of temperature and magnetic fields. These nanoscale structures exhibit remarkable stability, compactness, and energy efficiency, making them ideal for high-density, low-power memory applications.

By leveraging skyrmions, Marco’s research aims to overcome some of the core limitations of traditional storage, such as thermal energy loss and restricted scalability.

The role of skyrmions in advancing future electronics

To bring skyrmion-based racetrack memory closer to practical application, Marco Vás and his collaborators have been working across multiple ANSTO facilities, including the Australian Centre for Neutron Scattering (ACNS) and the Australian Synchrotron, to improve the properties of a promising material: Cu₂OSeO₃ (copper oxide selenite).

Cu₂OSeO₃ is the only known insulating material that can host magnetic skyrmions. Unlike traditional silicon-based materials, its insulating nature reduces energy loss to heat, improving its energy efficiency and thereby reducing its environmental footprint.

However, to make this material suitable for real-world data storage applications, researchers need to understand and control two key factors:

• How its atomic structure influences skyrmion formation, and
• How to modify this structure to optimise the skyrmion formation conditions.

Marco addressed both challenges using a technique called elemental doping, where specific atoms in a material are substituted with atoms of a different element to alter the material’s properties. In this case, larger tellurium atoms were used to partially replace the smaller selenium atoms in Cu₂OSeO₃. This substitution expanded the material’s crystal lattice and weakened the interactions between copper atoms, thereby fine tuning the conditions required for the formation of stable skyrmions.

To confirm the desired structural changes had been achieved, Marco used the Powder Diffraction beamline at ANSTO’s Australian Synchrotron, along with the Wombat and Echidna neutron powder diffractometer beamlines at ACNS. These advanced tools allowed him to accurately characterise the crystal structure of the doped material under varying temperatures and magnetic fields. His results showed that tellurium was successfully incorporated into the crystal structure, slightly increasing the spacing between copper atoms.

To evaluate the impact of this doping on skyrmion behaviour, Marco used the Quokka small-angle neutron scattering (SANS) instrument at ACNS. His experiments revealed that skyrmions still formed in the doped material, at lower temperatures and under weaker magnetic fields than was required in the original undoped material. This result means that using doped Cu₂OSeO₃ lowers the electrical energy requirements to generate the necessary magnetic field for skyrmion formation.

Overall, tellurium doping improved the energy efficiency of skyrmion formation without compromising the material’s essential magnetic properties, demonstrating a significant step forward in developing low-power, high-density memory devices using spintronic technologies.

Innovative materials that will drive a sustainable future

From the digital cloud to the core of our devices, the future of sustainable computing depends on reimagining the materials that make it all possible. Spintronic technologies, powered by electron spin and magnetic interactions, offer a compelling path forward.

Marco’s research contributes to the development of promising new-generation materials that could transform how we store, process, and manage the world’s growing digital footprint.

AINSE are proud to spotlight Marco for his innovative work!

If you, like Marco, are interested in tackling major problems with atomic solutions, visit ainse.edu.au/scholarships to see how AINSE can support you.

To keep exploring AINSE’s research spotlights head to ainse.edu.au/research-spotlight.

Stay tuned for our next Magnetic May article, featuring Kyle Portwin’s research on enhancing thermo-electric materials with magnetic nanoparticles.

Follow ainse_ltd on Instagram, Facebook, Threads and LinkedIn to keep up to date with upcoming events and research spotlights.