Single-angle ptychography allows 3-D imaging of stressed materials
Everyone reacts differently under stress—even the relatively orderly atoms in a crystal. If scientists could get a clear picture of how planes of atoms shift and squeeze under stress, they could make use of those properties to provide emerging technologies, like nanoelectronics and next-generation semiconductor components, with extra speed or functionalities. However, creating this picture requires new techniques for imaging atoms in materials and their behavior in different environments.
In a recent collaborative study from the Institut Fresnel, IBM and the U.S. Department of Energy's (DOE) Argonne National Laboratory, scientists developed a new form of imaging that uses X-ray diffraction patterns, called single-angle Bragg ptychography.
Although Bragg ptychography and especially X-ray diffraction have been around for a while, single-angle Bragg ptychography allows for easier reconstruction of 3-D data about how strain affects a material.
In X-ray diffraction, the atoms within a material "scatter" the incoming X-rays, producing a signal on a detector. Because there are so many overlapping diffraction events happening simultaneously, it can be hard to identify the contribution of a particular small region of the lattice to the overall signal. To compensate for this, scientists use a method called Fourier analysis, which essentially converts the overall signal to a series of waves with peaks and valleys that correspond to the relative intensities of various parts of the signal.
