scholarly journals Magnetic Domain Patterns in Bilayered Ribbons Studied by Magnetic Force Microscopy and Magneto-Optical Kerr Microscopy

Scanning ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Jana Trojková ◽  
Ondřej Životský ◽  
Aleš Hendrych ◽  
Dmitry Markov ◽  
Klára Drobíková

The magnetic domain patterns of amorphous bilayered FeSiB/FeNbSiB and FeNbCuSiB/CoSiB ribbons are observed and analysed using the magneto-optical Kerr microscopy (MOKM) and magnetic force microscopy (MFM). Both microscopic techniques are highly sensitive to the sample surface; possibility of Kerr microscopy to visualize the domains separately in both layers is achieved by focusing the laser spot on the ribbon cross section. Wide curved domains as well as fine fingerprint domains were detected at the surface of ribbons due to presence of local stresses coming from the preparation process. With respect to high lateral resolution of MFM and its out-of-plane magnetization sensitivity, the perpendicularly magnetized crossed stripe domain patterns can be selected as well. Coiling of the ribbons on the half-round-end sample holder is often used to induce and control the magnetic anisotropy of these alloys. Changes in the magnetic domain structure at the outer-coiled surface and its dependence on the sign of magnetostriction coefficient are discussed in detail. Finally, the MFM images in the presence of external in-plane magnetic field up to ±40 kA/m are shown.

1999 ◽  
Vol 577 ◽  
Author(s):  
A. Gavrin ◽  
C. Sellers ◽  
S.H. Liouw

ABSTRACTWe have used Magnetic Force Microscopy (MFM) to study the magnetic domain structures of melt-spun Nd-Fe-B ribbons. The ribbons are commercial products (Magnequench International, Inc. MQP-B and MQP-B+) with a thickness of approximately 20 microns. These materials have identical composition, Nd12.18B5.36Fe76.99Co5.46, but differ in quenching conditions. In order to study the distribution of domain sizes through the ribbon thickness, we have prepared cross-sectional samples in epoxy mounts. In order to avoid artifacts due to tip-sample interactions, we have used high coercivity CoPt coated MFM tips. Our studies show domain sizes typically ranging from 50-200 nm in diameter. This is in agreement with studies of similar materials in which domains were investigated in the plane of the ribbon. We also find that these products differ substantially in mean domain size and in the uniformity of the domain sizes as measured across the ribbon. While the B+ material shows nearly uniform domain sizes throughout the cross section, the B material shows considerably larger domains on one surface, followed by a region in which the domains are smaller than average. This structure is presumably due to the differing quench conditions. The region of coarse domains varies in thickness, disappearing in some areas, and reaching a maximum thickness of 2.75 µm in others. We also describe bulk magnetic measurements, and suggest that.


2011 ◽  
Vol 56 (1) ◽  
pp. 159-161 ◽  
Author(s):  
D. Płusa ◽  
M. Dośpial ◽  
D. Derewnicka-Krawczyńska ◽  
P. Wieczorek ◽  
U. Kotlarczyk

The Domain Structure of Die-Upset Anisotropic Magnet Based On Nd-(Fe, Co)-B Alloy The measurements of the recoil curves for the die-upset Nd-(Fe, Co)-B based magnets from different points on the magnetization and demagnetization curves have been carried out by means of the LakeShore vibrating sample magnetometer in an applied magnetic fields up to 2 T. From the recoil curves the so-called Wohlfarth's remanence relationship has been derived. From this it was deduced that the magnetic interaction existing between the magnet grains has a dipolar nature. The existence of the magnetic interaction has been confirmed by magnetic domain observations by using the magnetic force microscopy (MFM). In the area of interaction domains there is the fine scale magnetic contrast resulting from the dipolar interaction between neighboring grains.


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