By Ashwini Sakharkar 29 Nov, 2024
Collected at: https://www.techexplorist.com/new-method-analyses-magnetic-nanostructures-high-resolution/93669/
Researchers at Martin Luther University Halle-Wittenberg (MLU) and the Max Planck Institute of Microstructure Physics in Halle have developed a novel method that allows for high-resolution analysis of magnetic nanostructures. This innovative technique achieves a remarkable resolution of around 70 nanometers—well beyond the 500 nanometers limitation of standard light microscopes.
Such advancements are pivotal for revolutionizing the creation of new, energy-efficient storage technologies rooted in spin electronics.The video player is currently playing an ad.
Traditional optical microscopes are hindered by the wavelength of light, rendering them incapable of resolving details smaller than approximately 500 nanometers.
However, this new method breaks through that barrier by harnessing the anomalous Nernst effect (ANE) along with a metallic nanoscale tip. ANE generates an electrical voltage in a magnetic metal that is perpendicular to both the magnetization and the temperature gradient, empowering researchers to delve deeper into the nanoscale world.
“A laser beam focuses on the tip of a force microscope and thus causes a temperature gradient on the surface of the sample that is spatially limited to the nanoscale,” says Professor Georg Woltersdorf from the Institute of Physics at MLU. “The metallic tip acts like an antenna and focuses the electromagnetic field in a tiny area below its apex.”
This approach allows for ANE measurements with significantly improved resolution compared to traditional light microscopy. The microscopic images produced by the research team attain a resolution of approximately 70 nanometres. Earlier research has only focused on magnetic polarization within the sample plane.
However, the research team asserts that the in-plane temperature gradient is also important and enables the examination of out-of-plane polarization through ANE measurements.
To address this gap and validate the effectiveness of the ANE method for visualizing magnetic structures at the nanometre scale, the researchers employed a magnetic vortex structure. A notable benefit of this new technique is its compatibility with chiral antiferromagnetic materials.
“Our findings are significant for the thermoelectric imaging of spintronic components. We have already demonstrated this with chiral antiferromagnets,” says Woltersdorf. “Our method has two advantages: on the one hand, we have greatly improved the spatial resolution of magnetic structures far beyond the possibilities of optical methods. Secondly, it can also be applied to chiral antiferromagnetic systems, which will directly benefit our planned Cluster of Excellence’ Centre for Chiral Electronics’.”
In collaboration with Freie Universität Berlin, the University of Regensburg, and the Max Planck Institute of Microstructure Physics in Halle, MLU is seeking funding as part of the Excellence Strategy. The goal of the research is to establish the groundwork for innovative concepts in future electronics.
Journal reference:
- Atul Pandey, Jitul Deka, Jiho Yoon, Anagha Mathew, Chris Koerner, Rouven Dreyer, James M. Taylor, Stuart S. P. Parkin, Georg Woltersdorf. Anomalous Nernst Effect-Based Near-Field Imaging of Magnetic Nanostructures. ACS Nano, 2024; DOI: 10.1021/acsnano.4c09749
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