High-throughput, Chemical X-ray Microstructure Screening Center for Functional Glasses and Glass Ceramics

• Applicant: Professor Dr. Ralf B. Wehrspohn
• Subject Area: Synthesis and Properties of Functional Materials
• Term: from 2016 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 316987262

Lab-based X-ray microscopy (XRM) has reached a level where a spatial resolution of 50 nm can be used on a routine basis. As such, it has been utilized intensely for metals and alloys. A plethora of very challenging applications of this emerging microstructure-diagnostics technique is waiting to become investigated in the realm of complex oxides. Spatial resolution is considered to be sufficient for this class of materials. The bottleneck is that 3D distributions of elements in multicomponent systems such as glass ceramics as well as new approaches to sample preparation have to become available before XRM can be widely used to explore their microstructure. In order to facilitate chemically contrasted XRM of complex oxides, the following methodological advancement of the existing XRM technique is proposed: First, ultrashort-pulsed laser ablation is used to machine perfectly cylindrical samples possessing a plate-like reference volume at its one end. After ion-beam thinning, SEM-EDXS elemental maps of this reference volume are acquired in a second step. Third, a correlation software is used to superimpose XRM and SEM-EDXS data to end up with chemical XRM data. Using this significantly improved XRM core facility, basic research regarding the crystallization in glasses and other topics of current interest for complex oxides can be studied. The latter investigations clearly do profit from a (compared to TEM) much improved volume-to-surface ratio, allowing to monitor much more representative (and thus statistically significant) sample volumes. Moreover, the temporal evolution of one and the same volume of interest upon heat treatment can be tracked and samples annealed in a temperature gradient will help enhancing throughput. Exemplified by ten case studies of high relevance for basic research, the new workflow sketched above will be proved and made available as a user facility to the German community of scientists interested in the accelerated development of complex oxides with new properties. The experimental datasets obtain will not just be used to establish microstructure-property relationships, but also form the basis for integrated computational materials engineering approaches and help building a materials data space. As such, it will become pivotal for future materials developments.

• DFG Programme: Major Instrumentation Initiatives
• Major Instrumentation: Analytisches Röntgenmikroskop
• Instrumentation Group: 4070 Spezielle Röntgengeräte für Materialanalyse, Strukturforschung und Werkstoff-Bestrahlung
• Co-Investigators: Professor Dr.-Ing. Joachim Deubener; Professor Dr. Dirk Enke; Professor Dr. Peter Gumbsch; Professor Dr. Thomas Höche; Professor Dr. Dominique de Ligny; Professorin Dr. Ingrid Mertig; Dr. Ralf Müller; Professor Dr.-Ing. Hans Roggendorf; Professor Dr.-Ing. Christian Rüssel; Professor Dr. Stefan Schweizer