CTEM conventional transmission

Wash-coat separated from the cordierite monolith by scraping was examined directly by two electron microscopy techniques CTEM (Conventional Transmission Electron Microscopy) and STEM (Scanning Transmission Electron Microscopy). [Pg.815]

The transmission electron microscope is now well established as a useful tool for the characterization of supported heterogeneous catalysts(l). Axial bright-field imaging in the conventional transmission electron microscope (CTEM) is routinely used to provide the catalyst chemist with details concerning particle size distributions, 3), particle disposition over the support material(2-6) as well as particle morphology(7). Internal crystal structure(8-10), and elemental compositions(ll) may be inferred by direct structure imaging. [Pg.360]

The use of the electron microscope over many years to obtain morphological and microstructural information is self-evident in this context, although it is arguable whether with such limited objectives the technique could be said to offer any more significant a contribution than any of the foregoing. Whilst the electron microscope per se yields, in the case of the conventional transmission variant (CTEM), images down to an atomic level, it is differentiated from the techniques noted above because it makes no use of direct chemical information about the catalyst however, in common with them it is an instrument of vacuum technology. [Pg.84]

D. Auguie, M. Oberlin, A. Oberlin and P. Hyvemat, Microtexture of mesophase spheres as studied by high resolution conventional transmission electron microscopy (CTEM), Carbon, 18,337-346 (1980). [Pg.262]

As in the field of condensed matter sciences, polymer research has made extensive use of conventional transmission electron microscopy (CTEM) ever since its invention. Polymer research focuses on materials that mainly consist of carbon and other light elements. These materials are relatively weak electron scatterers and therefore give low mass thickness and phase contrast. Mass thickness contrast may be enhanced using an objective aperture, staining, and/or low... [Pg.48]

There are two main classes of electron micro.s-copy (EM) techniques. In the first class, the electron probe is a stationary beam incident along a fixed direction. This incident beam can be parallel [conventional transmission electron microscopy (CTEM), high-resolution transmission electron microscopy (HRTEM), high-voltage transmission... [Pg.1077]

TEM has two basic modes, one is conventional transmission electron microscopy (CTEM or TEM for short) mode using a broad beam, another one is scanning TEM (STEM for short) using a focused electron probe (by focusing the electron beam into a narrow spot) scanning across TEM specimen in a raster. [Pg.189]

Conventional transmission electron microscopes (CTEM or TEM) are electron optical instnunents analogous to light microscopes, where the specimen is illuminated by an electron beam. This requires operation in a vacuum because air scatters electrons. High resolution... [Pg.42]

Conventional and scanning transmission electron microscopy (CTEM and STEM) were done on a JEOL 100C electron microscope. The scanning (secondary emission) electron microscopy was done on a JEOL U3. [Pg.181]

Silica (Degussa Aerosil, 200 m /g) was used as the support material. Conventional electron microscopy (CTEM) was performed on a Oeol 100 CX microscope. It was used to determine the particles size of both supported monometallic and bimetallic catalysts. Scanning Transmission Electron Microscope (STEM) HB 5 from Vacuum Generator was used to characterize the bimetallic catalysts. Infrared spectra were obtained with a Nicolet 10 MX-1 Fourier transform instrument. It was used to characterize the alkyl groups evolution on the surface during reaction between Rh/Si02 and Sn(n-C Hg). ... [Pg.718]