ISSN:0741-0581    

DOI:10.1002/jemt.1060110302

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractExperimental results obtained by electron diffraction (ED) and extended electron energy loss fine structure (EXELFS) techniques to study the local atomic order in amorphous materials such as carbon, silicon, and its oxides are described. Potential applications of ED and EXELFS techniques and their limitations are also discussed.

ISSN:0741-0581    

DOI:10.1002/jemt.1060110303

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractA magnetic‐field‐superimposed field emission gun with low aberrations and equipped with a zirconiated tungsten emitter has been developed for applications where very stable high probe currents are required. It has been tested on a conventional electron microscope at 10 kV and on an electron beam testing system at 1 kV. Probe current i = 250 nA in a probe size d = 0.4 μm is obtained at 10 kV; at 1 kV the resolution is 0.1 μm with i = 5 nA, and 0.4 μm with i = 30 nA. For these probe currents, the spatial broadening effect due to electron–electron interactions in the beam is the preponderant factor limiting the pr

ISSN:0741-0581    

DOI:10.1002/jemt.1060110304

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractExperiments on automating the transmission electron microscope rely on the search for minimum variance. This image parameter gives satisfactory results for automatic focusing, astigmatism correction, and beam alignment. We investigate here the different image descriptors that might also be used; we conclude that texture parameters, which are directional, would be better candidates correcting astigmatism and beam tilt.

ISSN:0741-0581    

DOI:10.1002/jemt.1060110305

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThe properties of oxides may be drastically influenced by their microstructures. Thus the knowledge of nonstoichiometric mechanisms is an essential tool for the conception of new inorganic compounds by solid‐state chemist. Through three chosen examples of complex oxides with perovskite‐related structure, these points are illustrated. The new families of phosphate tungsten bronzes, the antiferromagnetic AMn1 − xFexO3 – y, and the copper oxides LCuO3 – x(La = Ba, Y, La) were studied by high‐resolution electron microscopy (HREM) in order to analyze the mechanisms of nonstoichiometry, the defects of which can modify their physical properties (magnetism or electronic conductivity) and the factors that govern their st

ISSN:0741-0581    

DOI:10.1002/jemt.1060110306

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractUsing an instrument equipped with two electron guns, an electron analyzer, and a Si(Li) diode detector, we developed microanalytical techniques based on inner‐shell electron excitations by incident electrons and X‐rays, that is, electron energy‐loss spectroscopy (EELS) in the reflection mode; electron probe microanalysis (EPMA) and X‐ray appearance potential spectroscopy (XAPS); electron‐induced Auger electron spectroscopy (e‐AES); X‐ray photoelectron spectroscopy (XPS), X‐ray absorption spectroscopy (XAS); X‐ray induced AES (XAES), X‐ray fluorescence analysis (XRF), and scanning X‐ray radiography (SXR). The corresponding characteristic images (including X‐ray microradiography and X‐ray photoelectron microscopy) were obtained in the scanning mode. The principle of the apparatus is described. Each spectroscopy and microscopy is illustrated by an example. Their performance

ISSN:0741-0581    

DOI:10.1002/jemt.1060110307

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractRibbon against drop (R.A.D.) ribbons exhibit a polycrystalline texture similar to that of most melt‐grown ribbons; we review here the defects of as‐grown materials as well as after the solar cells' product

ISSN:0741-0581    

DOI:10.1002/jemt.1060110308

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractAn application of high‐resolution transmission electron microscopy (HRTEM) to the study of two types of dislocations in potassium feldspars (K‐feldspars) is shown here. HRTEM images were submitted to a filtering in order to improve their interpretation. One type of dislocation—(010)[001]/2—appears to be dissociated, with (010)[001]/2 planar defect, whereas the other one—(010)[110]/2—is perfect. This result helps provide an understanding of dislocation activation in th

ISSN:0741-0581    

DOI:10.1002/jemt.1060110309

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThe first stages of crystallization have been investigated for a glass in the system SiO2‐Al2O3‐Li2O with small amounts of titanium and zirconium as nucleating elements. The studies were performed by electron diffraction and electron microscopy in high‐resolution mode. It has been found that the two phases forming the final glass ceramic crystallize successively. The first one gives small crystallites (<5 nm) randomly dispersed. The lattice plane images in several orientations are in good agreement with TiZrO4crystal lattice. At 780°C the average crystal size increases with increasing time of the heat treatments from 2.5 nm at 0.5 h to 4.5 nm at 2 h and then remains nearly constant. The crystallization of the second phase, a silicate solid solution with β‐quartz structure, occurs after complete crystallization

ISSN:0741-0581    

DOI:10.1002/jemt.1060110310

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

ISSN:0741-0581    

DOI:10.1002/jemt.1060110301

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY