UOsaka Researchers engineer atomic spacing in nanofilms on flexible substrates, opening doors to novel material properties

Osaka, Japan - Scientists at The University of Osaka and Tohoku University have developed a groundbreaking technique for creating nanoscale magnetic thin films with embedded functionality. By leveraging the stretchability of flexible substrates, they can precisely control the atomic spacing within these nanofilms, effectively “programming” desired magnetic properties directly into the material. This innovative approach, published in Applied Physics Letters, overcomes limitations of conventional deposition methods and paves the way for advancements in various fields, from electronics to fundamental materials science.

Creating nanofilms with specific functionalities typically relies on complex processes and material selection. Existing methods often restrict the range of achievable properties and can be challenging to implement. This new technique offers a simpler, more versatile solution.

The researchers deposit a magnetic nanofilm, such as cobalt or nickel, onto a pre-stretched flexible substrate. Upon releasing the tension, the substrate contracts, compressing the nanofilm and altering its atomic spacing. This controlled compression directly influences the magnetic anisotropy of the film, enabling the researchers to fine-tune its magnetic behavior. Experiments showed that greater substrate stretching led to a stronger embedded magnetic anisotropy. Furthermore, they successfully created a bilayer structure with perpendicular magnetization directions, potentially beneficial for magnetic sensors and strain gauges.

This ability to tailor magnetic properties at the nanoscale has significant implications. It opens doors to developing novel magnetic materials with customized functionalities, beyond what is achievable with traditional methods. Moreover, the technique’s simplicity and adaptability extend its potential to a wide range of materials beyond magnets, including superconductors, semiconductors, and dielectrics. This versatility promises to impact various fields, including flexible electronics, a crucial area for medical and healthcare applications, and energy-efficient electronics, vital for addressing the growing power consumption of AI and data centers.

Dr. Daichi Chiba, leading the research, stated, "Even materials that appear rigid in bulk form can become surprisingly flexible at the nanoscale. By harnessing this inherent flexibility, we can manipulate atomic spacing and fundamentally alter material properties. This approach of 'embedding' functionality during fabrication represents a new frontier in materials science, allowing us to tailor materials for specific applications with unprecedented control."

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The article, “Tailoring magnetic anisotropy via built-in strain in thin films,” was published in Applied Physics Letters at DOI: https://doi.org/10.1063/5.0279452