Tackling grand challenges in the materials science of liquids and glasses and non-equilibrium magnetism.
Wisconsin MRSEC Research Experience for Teachers 2022 fellow Lalitha Murali leveraged her connection with Jason Kawasaki in Wisconsin MRSEC IRG 2 and support from a Agris-Pine grant from the Society for Science to arrange science project mentors for 7th grade students from her Title I school in Milwaukee.
Wisconsin MRSEC researchers have designed and fabricated a new dual-gate 1200 V GaN based bidirectional transistor with good performance. However, performance is limited by failure of the electrically insulating layer, which is currently amorphous silicon nitride (SiN), a conventional material. In the next generation of devices, the team has replaced SiN with a crystalline strontium titanate membrane (SrTiO3) developed by MRSEC IRG 2. SrTiO3 is a much better insulator, so the team expects record performance in ongoing device testing.
Wisconsin MRSEC researchers have create an artificially magnetic material by alternating layers of Mn3GaN and Mn3Ga in perfect atomic registry with one another. The resulting material offers best-of-both worlds performance for advanced electronic devices based on spin. Their magnetism is easy to switch to encode information, but it is stable once set to a specific state. These outstanding properties arise both from the properties of the layers themselves and from the unique atomic environments that exist where the two layers meet. As a result, combining materials this way lets materials scientists design materials that cannot otherwise exist.
Polycrystalline materials are everywhere in everyday life, but their microstructure – the arrangement of atoms into crystal grains and grains into a piece of material – covers 10 orders of magnitude in size and involves millions important features. This complexity makes it extremely difficult for scientists to predict the properties of polycrystalline materials quickly and accurately. Wisconsin MRSEC researchers have leveraged the power of machine learning to tame the complexity of polycrystalline materials and predict their properties. They have developed a graph neural network approach that predicts materials properties with >98% accuracy 90,000 times faster than competing methods. They applied this model to predict magnetostriction, which quantifies the size change of a material induced by a magnetic field. Development and design of high magnetostriction materials will enable MRSEC researchers to efficiently control magnetism using mechanical force and enable future technologies such like magnetic soft robots
Physical vapor deposition (PVD) canproduce glassthinfilmswith preferred orientation to the molecules andhigherdensitythan ordinaryliquid-quenchedglass bytakingadvantageofthefastmovementoforiented moleculesonthe glasssurface. Research supported by Wisconsin MRSEC have found a new way to control the structure and properties of these films by growing them on soft substrates. PVD on a soft substrate can produce glass thin films that are much more dense and stable than those deposited on rigid substrates. A film deposited on a soft substrate in 2 hours is equivalent to a film deposited extremely slowly on rigid substrates over ~3000 years.
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