Nanoscale magnetic domains in mesoscopic dots: Experimental and theoretical investigations of zero field domain structures

1996 ◽  
Vol 163 (3) ◽  
pp. 5-8
Author(s):  
M. Hehn ◽  
R. Ferré ◽  
K. Ounadjela ◽  
J.-P. Bucher ◽  
F. Rousseaux
Keyword(s):  
Zero Field ◽  
Magnetic Domains ◽  
Domain Structures ◽  
Theoretical Investigations

Magnetic domains along shear bands in amorphous metals observed by spin-polarized scanning electron microscopy

1993 ◽  
Vol 8 (4) ◽  
pp. 775-784 ◽  
Author(s):  
W.J. Tseng ◽  
K. Koike ◽  
J.C.M. Li
Keyword(s):  
Easy Axis ◽  
Shear Bands ◽  
Stress Fields ◽  
Magnetic Domains ◽  
Magnetic Islands ◽  
Mode Iii ◽  
Similar Shape ◽  
Domain Structures ◽  
Spin Polarized ◽  
Scanning Electron

A novel spin-polarized scanning electron microscope with capabilities of observing microscopic domain structures and determining in-plane magnetization directions has been used to investigate the stress-induced magnetic domains in the Fe78B13Si9 (Allied 2605-S2) metallic glass. The magnetic structure in the vicinity of shear bands that are produced near a Mode III crack has been examined. On the tensile side of bending, arrays of individual, discontinuous magnetic “islands” of similar shape and size (about 2–10 μm in length, 3 μm in width, and spaced about 2–4 μm apart) are uniformly distributed on one side of the shear bands. Their easy axis is about parallel to the shear bands. On the other hand, well-defined elliptical domains are found between shear bands on the compression side of bending. Their easy axes are approximately perpendicular to the shear bands. These results suggest the existence of isolated defects of similar stress fields located along the shear bands. The possibility that these defects are dislocations will be investigated next.

Tem Study of Twinning and Magnetic Domains in Terfenol-D

1994 ◽  
Vol 360 ◽  
Author(s):  
Jennifer Dooley ◽  
M. De Graef
Keyword(s):  
Magnetic Domain ◽  
Objective Lens ◽  
Magnetic Domains ◽  
Domain Structures ◽  
Low Field ◽  
Enhanced Resolution ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
Observational Mode ◽  
Lorentz Transmission Electron Microscopy

AbstractThis paper reports the results of detailed TEM observations on [211] oriented single crystal samples of Terfenol-D. Domain structures are interpreted in terms of recent micromagnetic models developed by James and Kinderlehrer. Lorentz transmission electron microscopy was performed on a JOEL 120CX equipped with a low field objective lens. We also report for the first time energy-filtered magnetic domain images, recorded using a Gatan Imaging Filter on a JOEL 40000EX high resolution TEM. This observational mode allows for enhanced resolution and improved image contrast.

Scanning electron microscopy with polarization analysis: An update

1991 ◽  
Vol 49 ◽  
pp. 764-765
Author(s):  
J. Unguris ◽  
M. W. Hart ◽  
R. J. Celotta ◽  
D. T. Pierce
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Domain Walls ◽  
Domain Wall Motion ◽  
Optical Recording ◽  
Polarization Analysis ◽  
Magnetic Domains ◽  
Magnetic Microstructure ◽  
Domain Structures ◽  
Scanning Electron

Over the past ten years the technique of scanning electron microscopy with polarization analysis (SEMPA) has rapidly evolved from a scientific curiosity to a useful analytical tool for looking at a material's magnetic microstructure. Several reviews of the technique have been published elsewhere. SEMPA has been successfully used to analyze various technological problems such as: noise in magnetic and magneto-optical recording media, domain wall motion in thin film recording heads, and domain structures in small Permalloy shapes. Basic science applications of SEMPA include quantitative studies of the influence of the surface on the structure of magnetic domains and domain walls, and studies of magnetic microstructures in ultra-thin (0.1 - 1 nm) ferromagnetic films. Many current applications of SEMPA make use of the technique's surface sensitivity to probe the magnetism of thin films and multilayers.

Magnetic Domains and Domain Wall Pinning in Nanocrystalline Ni-P

2001 ◽  
Vol 7 (S2) ◽  
pp. 1242-1243
Author(s):  
J.P. Zhang ◽  
Y.X. Guo ◽  
J.S. Speck
Keyword(s):  
Magnetic Domain ◽  
Control Mode ◽  
Objective Lens ◽  
Magnetic Domains ◽  
Lorentz Microscopy ◽  
Domain Structures ◽  
Resolution Electron ◽  
Alloy Material ◽  
Electron Imaging ◽  
Fcc Structure

Magnetic domain structures in a Ni-5at%P alloy have been examined using Lorentz microscopy in Fresnel mode in a JEOL 2010TEM. with electron diffraction and high resolution electron imaging, the Ni-P alloy material is seen to be of FCC structure and composed of nanometer-sized grains (< 4nm in diameter), which is about 2 orders less in size than that of a single magnetic domain.The TEM specimen was prepared using jet polishing method. Before introducing the specimen into the microscope, the objective lens was turned off in a free lens control mode to ensure that the domain structures in the specimen remain unaffected. The objective mini-lens was used to perform Lorentz imaging with out-focus method.Stripe domains were observed. The width of these stripes is about 0.2 micron. But the length of these domains varies, sometime up to several microns. The stripe domains are grouped, which are near parallel one to the other.

Mapping of Magnetic Domains by MFM in Ni2MnGa

2008 ◽  
Vol 52 ◽  
pp. 115-119 ◽  
Author(s):  
Deepti Jain ◽  
Soma Banik ◽  
L.S. Sharath Chandra ◽  
S.R. Barman ◽  
R. Nath ◽  
...  
Keyword(s):  
Domain Walls ◽  
Alloy System ◽  
Optical Microscope ◽  
Magnetic Domains ◽  
Local Magnetization ◽  
Force Microscopy ◽  
Domain Structures ◽  
Two Samples ◽  
Ferromagnetic Shape Memory ◽  
Curie Temperature Tc

Influence of structural transition in the evolution of the magnetic domains in the ferromagnetic shape memory alloy system Ni2+xMn1-xGa is reported here using Magnetic Force Microscopy (MFM) studies. Studies reported are with two samples with their martensite transition temperature TM less than and greater than the Curie temperature Tc. Present results show an evolution of MFM across the Tc with a clear twin domains and sub domain structures inside the twins. The higher spatial resolution of MFM (~50nm) as compared to optical microscope (400nm) is useful in probing the domain walls. Force derivative of the MFM signal that may be used as an order parameter seems to scale the onset of magnetic order in the system. One can clearly see the vanishing of the MFM patterns for T>Tc. Results are discussed in the light of models available for tip-sample interactions that track the local magnetization.

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