By Will Soutter
Scientists from the Argonne National Laboratory’s Advanced Photon Source and Center for Nanoscale Materials have developed a new X-ray imaging technique that incorporates 3D visualization of a material’s surface without damaging the sample under study.
The innovative imaging technique expands the scope of x-ray research of nanotechnology and biology and is a combination of the benefits of high resolution characteristics of X-ray coherent diffraction imaging (CDI) sans lens and 3D surface visualization facilitated by grazing-incident geometry scattering.
The atomic interactions that determine the characteristics and effectiveness of a self-assembled nanostructure or nanotechnology based semiconductor product mostly occur at or below the surface of the material. In the past, scientists have had to depend on simulated models to determine the surface structure and thickness, wherein complete confidence in integrity of such measurement was lacking.
The scientists at Argonne enabled 3D viewing of the surface using the new technique by manipulating the angle at which X-rays scatter off the sample material. Employing grazing-incident geometry instead of conventional CDI transmission geometry, the scattering pattern was used to generate a three dimensional image without resorting to modeling. Though traditional X-ray imaging techniques are capable of producing 3D images, the resolution of the image is poor and the intensity of the X-rays can damage the samples.
Since the new technique requires just one x-ray short to form the image, it makes it a desirable, non-destructive technique for analysis of biological samples. Another key benefit of the new technique is that the scope of imaging using CDI can be increased from nanoscale to millimeter scale if the X-ray is incident at a glancing angle on the sample. This unique technique enables researchers to extend the behavior at atomic or molecular level to behavior at device level.