Magnetic Material Observation Assembly for Tem with a Eucentric Goniometer

1976 ◽  
Vol 34 ◽  
pp. 540-541
Author(s):  
K. Shi rota ◽  
A. Yonezawa ◽  
K. Shibatomi ◽  
T. Yanaka
Keyword(s):  
Magnetic Material ◽  
Electron Microscope ◽  
Magnetic Domain ◽  
Objective Lens ◽  
Magnetic Domains ◽  
Lorentz Microscopy ◽  
Transmission Electron ◽  
Correction Of Astigmatism ◽  
Single Orientation ◽  
Conventional Transmission Electron Microscope

As is well known, it is not so easy to operate a conventional transmission electron microscope for observation of magnetic materials. The reason is that the instrument requires re-alignment of the axis and re-correction of astigmatism after each specimen shift, as the lens field is greatly disturbed by the specimen. With a conventional electron microscope, furthermore, it is impossible to observe magnetic domains, because the specimen is magnetized to single orientation by the lens field. The above mentioned facts are due to the specimen usually being in the lens field. Thus, special techniques or systems are usually required for magnetic material observation (especially magnetic domain observation), for example, the technique to switch off the objective lens current and Lorentz microscopy. But these cannot give high image quality and wide magnification range, and furthermore Lorentz microscopy is very complicated.

Resolution of a Transmitted Electron Image Formed by A Scanning Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 386-387
Author(s):  
S. Takashima ◽  
H. Hashimoto ◽  
S. Kimoto
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Objective Lens ◽  
Specimen Thickness ◽  
Probe Diameter ◽  
Transmission Electron ◽  
Electron Image ◽  
Conventional Transmission Electron Microscope ◽  
Scanning Electron

The resolution of a conventional transmission electron microscope (TEM) deteriorates as the specimen thickness increases, because chromatic aberration of the objective lens is caused by the energy loss of electrons). In the case of a scanning electron microscope (SEM), chromatic aberration does not exist as the restrictive factor for the resolution of the transmitted electron image, for the SEM has no imageforming lens. It is not sure, however, that the equal resolution to the probe diameter can be obtained in the case of a thick specimen. To study the relation between the specimen thickness and the resolution of the trans-mitted electron image obtained by the SEM, the following experiment was carried out.

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.

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.

Lorentz Microscopy: Effect of Tilting on Magnetic Domains in Single Crystal Iron Films

1968 ◽  
Vol 26 ◽  
pp. 388-389
Author(s):  
L. F. Allard ◽  
A. P. Rowe ◽  
P. L. Fan
Keyword(s):  
Single Crystal ◽  
Domain Walls ◽  
Magnetic Domain ◽  
Objective Lens ◽  
Pole Piece ◽  
Magnetic Domains ◽  
Iron Films ◽  
Lorentz Microscopy ◽  
Magnetic Domain Walls ◽  
Microscopy Techniques

In order to observe magnetic domain walls by Lorentz microscopy techniques it is often necessary either to operate the microscope with the objective lens off, thus severely limiting the magnification, or to move the specimen from its usual position or make some other modification so that the field to which it is subjected is not so strong that it saturates the specimen. However, conditions in the JEM-6A have proved favorable for observation of domains in single crystal iron films by the out-of-focus method without any modifications, using either the regular specimen stage with the small bore pole piece or the tilting stage with the large bore pole piece. The tilting stage is particularly useful for these studies because the domains are very sensitive to small differences in inclination in the field.

Contrast Considerations in Environmental Cells

1973 ◽  
Vol 31 ◽  
pp. 20-21
Author(s):  
J. R. Sellar
Keyword(s):  
Electron Microscope ◽  
Multiple Scattering ◽  
Chromatic Aberration ◽  
Objective Lens ◽  
Noise Effects ◽  
Transmission Electron ◽  
Environmental Cell ◽  
A Cell ◽  
Conventional Transmission Electron Microscope

To study chemical reactions in situ and observe biological specimens in the hydrated state, it is necessary to isolate the specimen from the vacuum of the electron microscope by means of a cell. Figure 1 represents such a cell in a conventional transmission electron microscope (CTEM) with apertures or windows A, specimen mounting B, and specimen T. O labels the objective lens, L the cell gas, and S is the width of the layer of gas.Calculations have been carried out involving the contrast available when thick specimens are imaged or an environmental cell is used at 1000 keV. For the limitations considered, including multiple scattering, chromatic aberration and the effects of various geometrical configurations, it appears that, in the absence of noise effects due to loss of intensity, multiple scattering causes the largest disc of confusion.

Observability of Very Thick Specimen by Using Transmission Scanning Electron Microscope

1971 ◽  
Vol 29 ◽  
pp. 26-27
Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike
Keyword(s):  
Electron Microscope ◽  
Image Quality ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Image Contrast ◽  
Objective Lens ◽  
Thick Specimen ◽  
Transmission Electron ◽  
Scanning Electron

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.

Development of 200 kV Scanning-Transmission Electron Microscope

1974 ◽  
Vol 32 ◽  
pp. 410-411
Author(s):  
H. Koike ◽  
S. Sakurai ◽  
K. Ueno ◽  
M. Watanabe
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
The Other ◽  
Morphological Observation ◽  
Magnetic Domains ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Backscattered Electron ◽  
Increasing Demand

In recent years, there has been increasing demand for higher voltage SEMs, in the field of surface observation, especially that of magnetic domains, dislocations, and electron channeling patterns by backscattered electron microscopy. On the other hand, the resolution of the CTEM has now reached 1 ∼ 2Å, and several reports have recently been made on the observation of atom images, indicating that the ultimate goal of morphological observation has beem nearly achieved.

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