Identification of spatial magnetic inhomogeneities by nuclear forward scattering of synchrotron radiation

• Published in: Journal of synchrotron radiation Vol. 26; no. 4; pp. 1310 - 1315
• Main Authors: Vrba, Vlastimil, Procházka, Vít, Miglierini, Marcel
• Format: Journal Article
• Language: English
• Published: 5 Abbey Square, Chester, Cheshire CH1 2HU, England International Union of Crystallography 01-07-2019; John Wiley & Sons, Inc
• Subjects: Amorphous materials; Forward scattering; Inhomogeneity; magnetic inhomogeneities; Magnetic moments; Metallic glasses; Mössbauer spectroscopy; nuclear forward scattering; rotational invariance; Spatial distribution; Synchrotron radiation; nuclear forward scattering; magnetic inhomogeneities; metallic glasses; Mössbauer spectroscopy; rotational invariance
• ISSN: 1600-5775; 0909-0495; 1600-5775
• DOI: 10.1107/S1600577519005344

Spatially confined magnetic inhomogeneities were revealed by measuring nuclear forward scattering time spectra on the same sample in two different geometric arrangements. They differ by 180° rotation of the sample around one of the polarization axes. A basic theoretical description of this phenomenon and its relation to a spatial distribution of nuclei featuring different magnetic moments is provided. From an experimental point of view, the violation of rotational invariance was observed for an inhomogeneous Fe81Mo8Cu1B10 metallic glass. The development of magnetic inhomogeneities and their relation to the evolution of time spectra was studied during thermal annealing.
Nuclear forward scattering of synchrotron radiation allows the identification of inhomogeneities of hyperfine interactions in the bulk of a material. The inhomogeneities could cause violation of rotational invariance, i.e. differences in the time spectra measured under two different geometric arrangements.