Seminars Archive

Highlights of in situ high-temperature X-ray microtomography applied to geosciences using a new induction furnace at Elettra

Abstract
In situ high-resolution studies of materials at high-temperature using synchrotron and laboratory X-ray microtomography (mCT) have in recent years become an important tool for studying material behaviour and help to interpret textures found after quench. At Elettra, an induction furnace has been designed and constructed to perform X-ray mCT experiments, with special attention placed on its flexibility, precise temperature calibration and long runtime ability - both crucial for many material science and geoscience applications. The furnace has been optimized and tested with the collaboration of the Dept. of Earth and Planetary Sciences at the McGill University of Montréal (Canada). Here we would like to present two examples, where the use of the new induction furnace showed promise of answering some longstanding geoscience questions. One of the applications of this furnace is high-temperature experimental study of platinum (Pt) nuggets formation, growth and stability in magmatic conditions. Pt is a material of extreme importance to many economic and industrial aspects of our society, ranging in use from medicine to electronics. It also holds an important scientific value as a geochemical tracer, that allows us to study differentiation processes of the rocky part of our solar system. One of the key challenges in experimental studies of Pt is its affinity to form micrometer sized nuggets in silicate melts. This creates problems in analytical quantification of rocks due to inhomogeneous distribution, but also in material sciences where Pt nugget formation poses a challenge in glass production. The second example shows how this furnace can be applied at the SYRMEP beamline of Elettra to study the nucleation and growth of plagioclase crystals. Plagioclase is one of the most abundant minerals on Earth, however the growth rates and the nucleation lag time is not well quantified. As one of the very first minerals to form upon magma cooling, the conditions of its formation and growth have profound effects on the subsequent magma development, either in conditions of calm rise within the crust or explosive development before a volcanic eruption. With a high-temperature X-ray mCT set up like the one developed at Elettra, it is possible to control the temperature precisely and run the furnace long enough to observe and quantify the nucleation of plagioclase. Any in situ high-resolution X-ray mCT studies with this type of furnace are an irreplaceable tool in studying these processes that could not be observed in any other way, and provide the next step in material and geoscience research.