Subpercent Local Strains Due to the Shapes of Gold Nanorods Revealed by Data-Driven Analysis

When the strain starts to show

28 February 2022

The strain experienced by individual atoms located across the curved surface of a nanoparticle can now be calculated to an unprecedented precision.

The properties of nanomaterials are often significantly affected by the atomic-scale strain that results when surface curvature squeezes atoms out of their ideal positions relative to their neighbours. While this strain can be calculated from scanning transmission electron microscopy (STEM) images that show atomic positions in nanomaterials, factors such as distortion and image noise limit calculation precision to around 1% strain.

Now, by enhancing STEM images, a team led by Kyushu University researchers has achieved a precision of 0.2% for strain measurements.

They realized this by using a data analysis approach called Gaussian process regression to enhance the STEM images and thereby create a truer atomic map.

The team experimentally determined the different strains experienced by surface atoms in the middle of a rod-shaped nanoparticle and by atoms at its ends.

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References

1. ACS Nano 15, 12077–12085 (2021). doi: 10.1021/acsnano.1c03413