Multi-instrumental approach to domain walls and their movement in ferromagnetic steels – Origin of Barkhausen noise studied by microscopy techniques

• DOI: 10.1016/j.matdes.2023.112308
• Publication Date: 2023-09-07T15:52:46Z
• Authors: Suvi Santa-aho; Mari Honkanen; Sami Kaappa; Lucio Azzari; Andrey Saren; Kari Ullakko; Lasse Laurson; Minnamari Vippola
• Keywords: Barkhausen effect

Two steels, ferrite and ferrite-pearlite were thoroughly characterized by a multi-instrumental microscopy techniques to get detailed information about their microstructure magnetic structure. Microstructural features act as pinning sites for the motion of domain walls (DWs) leading changes in magnetization sample. This phenomenon is basis industrially relevant non-destructive Barkhausen noise (BN) technique. With force (MFM), using bulk samples, Lorentz microscopy, thin films, we noticed that samples have similar structure still giving different BN signal amplitudes. We could explain an in-plane DW movement under out-of-plane applied field anisotropy energetics. In-situ transmission electron (TEM) mode was used visualize DWs interactions with sites. To help interpretation motions, alignment denoising processes tailored in-situ TEM studies. Multi-instrumental multidimensional structural analysis enabled us verify many theoretical hypotheses related origin steels.