Real time dynamic domain observation in bulk materials

Moses, Anthony John; Williams, P. I.; Hoshtanar, O.

doi:10.1016/j.jmmm.2006.02.117

Cited by 9 publications

(4 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Whilst the Bitter method is convenient and sensitive its resolution is relatively low (about 1 µm) 11 . This limits the application of the method for static domain patterns to steels that show DWs separate by >2 µm.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Optimized Setup and Protocol for Magnetic Domain Imaging with <em>In Situ</em> Hysteresis Measurement

Liu

Wilson

Davis

et al. 2017

JoVE

View full text Add to dashboard Cite

This paper elaborates the sample preparation protocols required to obtain optimal domain patterns using the Bitter method, focusing on the extra steps compared to standard metallographic sample preparation procedures. The paper proposes a novel bespoke rig for dynamic domain imaging with in situ BH (magnetic hysteresis) measurements and elaborates the protocols for the sensor preparation and the use of the rig to ensure accurate BH measurement. The protocols for static and ordinary dynamic domain imaging (without in situ BH measurements) are also presented. The reported method takes advantage of the convenience and high sensitivity of the traditional Bitter method and enables in situ BH measurement without interrupting or interfering with the domain wall movement processes. This facilitates establishing a direct and quantitative link between the domain wall movement processes–microstructural feature interactions in ferritic steels with their BH loops. This method is anticipated to become a useful tool for the fundamental study of microstructure–magnetic property relationships in steels and to help interpret the electromagnetic sensor signals for non-destructive evaluation of steel microstructures.

show abstract

Section: Discussionmentioning

confidence: 99%

“…Amongst various domain imaging techniques, the Bitter method, i.e. using fine magnetic particles to reveal magnetic DWs, has some obvious advantages including easy set-up and high sensitivity 11 . Due to the use of a medium, e.g.…”

Section: Introductionmentioning

confidence: 99%

Optimized Setup and Protocol for Magnetic Domain Imaging with <em>In Situ</em> Hysteresis Measurement

Liu

Wilson

Davis

et al. 2017

JoVE

View full text Add to dashboard Cite

show abstract

“…As transformers are operated at frequencies of power networks the analysis of their surface domains is done with dynamic observation techniques like excitation/scanning synchronization 3 and sampling stroboscopy 4 . Information about domain wall motion, wall spacing, bowing, nucleation and domain refinement of GOES at power frequencies are reported in 5 where stroboscopic and even real time experiments are reported all together using light-based Kerr microscopy techniques. The disadvantage of Kerr microscopy is that the insulating coating, which is used in most transformer steel cores, has to be removed for the analysis to expose the surface of the steel.…”

Section: Introductionmentioning

confidence: 99%

“…utilizing on light or electrons, makes it possible to study bulk behavior of magnetic domain walls while keeping the insulating coating intact and thus without modifying the domain structure. The dark-field image (DFI) of neutron grating interferometry (nGI) 9 recently emerged as a valuable complementary technique to the established domain observation methods because it is the only technique available that enables the spatially resolved analysis of bulk magnetic domain walls 5 , 12 – 15 deep in the volume of materials and thus provides unique information. The contrast is based on the small-angle scattering of neutrons at domain walls and the consequent disruption of a predefined interference pattern.…”

Section: Introductionmentioning

confidence: 99%

Dynamic volume magnetic domain wall imaging in grain oriented electrical steel at power frequencies with accumulative high-frame rate neutron dark-field imaging

Harti

Ströbl

Schäfer

et al. 2018

Sci Rep

View full text Add to dashboard Cite

The mobility of magnetic domains forms the link between the basic physical properties of a magnetic material and its global characteristics such as permeability and saturation field. Most commonly, surface domain structure are studied using magneto-optical Kerr microscopy. The limited information depth of approx. 20 nanometers, however, allows only for an indirect interpretation of the internal volume domain structures. Here we show how accumulative high-frame rate dynamic neutron dark-field imaging is able for the first time to visualize the dynamic of the volume magnetic domain structures in grain oriented electrical steel laminations at power frequencies. In particular we studied the volume domain structures with a spatial resolution of ∼100 μm and successfully quantified domain sizes, wall velocities, domain annihilation and its duration and domain wall multiplication in real time recordings at power frequencies of 10, 25 and 50 Hz with ±262.5 A/m and ±525 A/m (peak to peak) applied field.

show abstract