Transmission Electron Microscopy of Shear Band Formation in Rolled Copper Single Crystals

Bi-based superconducting phases have been found to be members of a structural series represented by Bi2Sr2Can−1Cun−1On+4, n=1,2,3, and are referred to as 2201, 2212, 2223 phases. All these phases are incommensurate modulated structures. The super space groups are P2/b, NBbmb 2201, 2212 phases respectively. Pb-doped ceramic samples and single crystals and Y-doped single crystals have been studied by transmission electron microscopy.Modulated structures of all Bi-based superconducting phases are in b-c plane, therefore, it is the best way to determine modulated structure and c parameter in diffraction pattern. FIG. 1,2,3 show diffraction patterns of three kinds of modulations in Pb-doped ceramic samples. Energy dispersive X-ray analysis (EDAX) confirms the presence of Pb in the three modulated structures. Parameters c are 3 0.06, 38.29, 30.24Å, ie 2212, 2223, 2212 phases for FIG. 1,2,3 respectively. Their average space groups are all Bbmb.

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Where are the geometrically necessary dislocations accommodating small imprints?

Journal of Materials Research ◽

10.1557/jmr.2009.0131 ◽

2009 ◽

Vol 24 (3) ◽

pp. 647-651 ◽

Cited By ~ 10

Author(s):

M. Rester ◽

C. Motz ◽

R. Pippan

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Twin Boundary ◽

Crystal Orientation ◽

Electron Backscatter Diffraction ◽

Transmission Electron ◽

Electron Backscatter ◽

Copper Single Crystals ◽

Backscatter Diffraction ◽

Small Misorientation

Electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) analyses of small indentations in copper single crystals exhibit only slight changes of the crystal orientation in the surroundings of the imprints. Far-reaching dislocations might be the reason for these small misorientation changes. Using EBSD and TEM technique, this work makes an attempt to visualize the far-propagating dislocations by introducing a twin boundary in the vicinity of small indentations. Because dislocations piled up at the twin boundary produce a misorientation gradient, the otherwise far-propagating dislocations can be detected.

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Conventional and high resolution transmission electron microscopy of NbC≈0.88 single crystals

Journal of the Less Common Metals ◽

10.1016/0022-5088(89)90360-3 ◽

1989 ◽

Vol 146 ◽

pp. 17-32 ◽

Cited By ~ 3

Author(s):

T. Epicier ◽

Y. Kumashiro

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

High Resolution ◽

Single Crystals ◽

Transmission Electron

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Identification of Faults in Asbestos Minerals and Application to Pollution Studies

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100093043 ◽

1976 ◽

Vol 34 ◽

pp. 616-617

Author(s):

K. Seshan ◽

H.-R. Wenk

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Single Crystals ◽

Twin Plane ◽

Fibre Axis ◽

Fibre Structure ◽

Asbestos Fibre ◽

Fibre Texture ◽

Transmission Electron ◽

Diffraction Patterns

Asbestos fibre texture occurs in various mineral groups (e.g. chrysotile, crocidolite, tremolite, grunerite, tourmaline) and it has been established that at least chrysotile is carcinogenic. We are investigating various aspects of the asbestos structure, with transmission electron microscopy (TEM) (1) in order to develop methods for unequivocal asbestos identification using minute samples and also to determine defects responsible for the fibre structure in these minerals which often occur as large, we 11-developed single crystals.In order to do this, we have started by investigating clinoamphibole asbestos such as tremolite Ca2Mg5[Si8O22] (OH, F)2 and crocidolite Na2 (Mg, Al, Fe3+, Fe2+) (Si8O22) (OH, F )2 , from California localities. In crocidoli te - asbestos we observed a high density of very narrow microtwins parallel to the fibre axis [001] (Fig. 1). They are often only 50-100Å wide. Diffraction patterns display the typical twin arrangement of spots and although preliminary contrast experiments are not yet conclusive the twin plane appears to be (100).

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