image: (left), 3D volume rendering (iso-surface) of the crystalline Si-star as retrieved from Bragg-ptychography, (center), atomic displacement along the z direction. The color map shows strain (dimensionless) (right) SEM image of the same Si-star sample, for comparison. view more
Credit: by P. Li, M. Allain, T. A. Grünewald, M. Rommel, A. Campos, D. Carbone and V. Chamard
It is the high brilliance of 4th generation synchrotrons which now makes high resolution 3D Bragg ptychography especially valuable for investigation of crystal samples, from biominerals found in teeth, bones, shells and more, to a diversity of technologically relevant materials exhibiting magnetic, ferro-electric, topological properties to cite a few.
“New microscopy tools can provide not only sharper images but allow completely new ways of studying extremely complex materials, improving our understanding of the world around,” said Dina Carbone, MAX IV scientist and study author. “This is the first step to produce technologies that truly responds to our needs in an efficient and sustainable way.”
The study, led by french scientist Virginie Chamard at Institut Fresnel, Aix-Marseille University, succeeded in producing a 3D image of the silicon crystalline sample with internal atomic deformations. The star is a well-known structure, chosen to assess the capabilities of the new Diffraction End-Station of NanoMAX previously designed by Carbone. The study team involved pioneered the 3D Bragg ptychography technique in 2011, and continues with its development.
The experiment’s sharp, quantitative imagery is primarily attributed to the unprecedented flux of coherent X-rays impinging on sample. The large datasets thus produced allow to overcome experimental limitations such as positioning errors or poor scanning conditions to obtain a high-resolution image of the sample. These circumstances are not possible to recreate at 3rd generation facilities, according to the study. “Intensity was a crucial component of this study, but not the only one. Appropriate data processing and image reconstruction routines had to be developed to reach this image quality, which took quite some effort.” said Peng Li, lead author of the study, now at Diamond Light Source (UK). These advances make Bragg ptychography compatible with a wider range of experimental set-ups at new synchrotron sources.
“Now it is time to strengthen the experimental and analytical competences of the user community interested in using such powerful microscopies. And this is a challenge and a responsibility of the light source facilities,” said Carbone. “We will be happy to help implementing this microscopy and make it available for a larger scientific community”, said Chamard.
The researchers are continuing their investigations with 3D microscopy at 4th generation sources, in the field of functional magnetic crystals and to investigate the intriguing structural properties of biominerals.
Journal
Light Science & Applications
Article Publication Date
25-Mar-2022