Articles by Marcel B. Miglierini in JoVE
Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses Marcel B. Miglierini1,2, Vít Procházka3, Vlastimil Vrba3, Peter Švec4, Dušan Janičkovič4, Peter Matúš5 1Institute of Nuclear and Physical Engineering, Slovak University of Technology in Bratislava, Slovakia, 2Department of Nuclear Reactors, Czech Technical University in Prague, Czech Republic, 3Department of Experimental Physics, Palacky University Olomouc, Czech Republic, 4Institute of Physics, Slovak Academy of Sciences, Bratislava, Slovakia, 5Institute of Laboratory Research on Geomaterials, Faculty of Natural Sciences, Comenius University in Bratislava, Slovakia Here, we present a protocol to describe ex situ and in situ investigations of structural transformations in metallic glasses. We employed nuclear-based analytical methods which inspect hyperfine interactions. We demonstrate the applicability of Mössbauer spectrometry and nuclear forward scattering of synchrotron radiation during temperature-driven experiments.
Other articles by Marcel B. Miglierini on PubMed
Evolution of Structure and Local Magnetic Fields During Crystallization of HITPERM Glassy Alloys Studied by in Situ Diffraction and Nuclear Forward Scattering of Synchrotron Radiation Physical Chemistry Chemical Physics : PCCP. Nov, 2015 | Pubmed ID: 25913178 Evolution of structure and local magnetic fields in (Fe(1-x)Co(x))76Mo8Cu1B15 (HITPERM) metallic glass ribbons with various amounts of Co (x = 0, 0.25, 0.5) were studied in situ using diffraction and nuclear forward scattering of synchrotron radiation. It was found that crystallization of all three glasses proceeds in two stages. In the first stage, bcc (Fe,Co) nanocrystals are formed, while in the second stage additional crystalline phases evolve. For all three glasses, the crystallization temperatures at the wheel side were found to be lower than at the air side of the ribbon. The crystallization temperatures were found to decrease with increasing Co content. The lattice parameters of the bcc nanocrystals decrease up to about 550 °C and then increase pointing to squeezing Mo atoms out of the nanograins or to interface effects between the nanocrystals and the glassy matrix. Nuclear forward scattering enabled separate evaluation of the contributions that stem from structurally different regions within the investigated samples including the newly formed nanocrystals and the residual amorphous matrix. Even minor Co content (x = 0.25) has a substantial effect not only upon the magnetic behaviour of the alloy but also upon its structure. Making use of hyperfine magnetic fields, it was possible to unveil structurally diverse positions of Fe atoms that reside in a nanocrystalline lattice with different numbers of Co nearest neighbours.