X-ray microscopy requires radiation of extremely high quality. To obtain sharp images, instrument and sample must stay absolutely immobile even at the nanometre scale during recording. Researchers at the Technische Universität München and the Paul Scherrer Institute in Villigen, Switzerland, have now developed a method that relaxes these hard restrictions. Even fluctuations in the material can be visualised. The renowned journal Nature now reports on their results (“Reconstructing state mixtures from diffraction measurements”).
Pierre Thibault of the Technische Universitüt München and Andreas Menzel, scientist at the Paul Scherrer Institute (Villigen, Switzerland) have now developed an interpretation method that produces reliable images in spite of vibrations or fluctuations. The method is based on a technique called “ptychography”, developed in the 1960s for electron microscopy. Thibault and Menzel’s advancements now make it possible to distinguish effects originating from the contribution of different types of X-ray waves.
Probably the most significant result of the study is that it gives access to a whole class of objects that previously could hardly be investigated. “We now not only can compensate for the vibrations in the microscope,” says Andreas Menzel. “We can even characterise fluctuations of the sample itself, even if they are much too fast to be seen with individual snapshots.”
“We needed to convince ourselves that the images we produced did indeed reflect accurately the samples and their dynamics,” says Pierre Thibault. “So we carried out computer simulations. They confirmed that effects of the instrument as well as of the sample itself, such as flows, switching events or mixed quantum states, can be characterised.”
Source: TU MünchenYvonne Klöpping