Epitaxial attachment

Fig. 7.4 High-resolution transmission electron microscopy (TEM) image of a rhodium on a modified cerium oxide (Ceo.gTbo.202 x) after reduction, showing how the metal is almost epitaxially attached to the support, (a) TEM image (b,c) digital diffraction patterns obtained by Fourier transformation from the images (d) structure model ...

In the discussions below, we shall see numerous examples of the results of epitaxial attachment. 

The use of NaCl as a mock-silver halide substrate has produced some of the most precise and striking surface determinations ever made, and has done so with a set of procedures remarkably free from criticality or difficulty (22). Historically, the use of NaCl was taken up in the hope of obtaining interpretable LEED patterns from dyed NaCl surfaces as an alternative to unsuccessful experiments on AgBr, where it appeared that the dye was decomposed by the combination of electron impact and the presence of a potentially oxidizing substrate (15). A clear diffraction pattern was obtained from the dyed NaCl however, since epitaxial dye islands were oriented in all possible directions on the crystal surface, the diffraction pattern of the host crystal was simply duplicated - though with an intensity much superior to undyed NaCl. In other words, the LEED experiment indicated only that an epitaxial attachment of dye had occurred. This we already felt we knew. 

It would be hard to find a clearer proof of epitaxial attachment. In the end of these considerations of epitaxial attachment, one is left with a certain appreciation for the comic figure of a befuddled man standing in the rain with a large ring of keys and trying to open his front door. When the right key (molecule) is found for the particular door (substrate), the result is most gratifying. 

The catalytic activity markedly depends on the contact structure of gold with the supports. Remarkably high activity emerges when hemispherical gold NPs are attached to the support at their flat planes. This contact structure is often epitaxial as... 

Much of the theory of scaling analysis was developed for molecular beam epitaxy (MBE), and there are some challenges in transferring the treatment to electrodeposition. In MBE, the incident atoms originate at a source at high temperature, arrive at the growth front from a vapor phase that is not in internal equilibrium, attach... 

The attachment of the MM to the CP will activate the mineralizing substrate and calcium carbonate crystals are laid down in epitaxial order. Crystal growth terminates upon secretion of a newly formed MM on the growing crystal surface whereby a kind of organic blanket is formed. Subsequently, CP becomes attached to MM. A sand-... 

A first array 12 consists of a substrate 16 composed of CdTe which has an upper liquid phase epitaxial layer 17 of p-type HgCdTe grown on it and a metallization layer 18 attached to a lower surface serving as an electrode. A plurality of mesas 20 composed of n-type HgCdTe are... 

An HgCdTe layer is epitaxially grown on a first substrate. An adhesive is used to attach the HgCdTe layer to a sapphire substrate, which absorbes infrared radiation. The first substrate is removed and the epitaxially grown HgCdTe layer is shaped by etching to form detector regions 14, which are connected by electrodes 15. Photons which are not absorbed by the detector elements will be absorbed in the sapphire substrate. 

Another factor which may change the alloying at the surface is the epitaxial strain of the surface alloy due to its pseudomorphic attachment to the substrate. This concerns especially systems with elements that differ considerably in size... 

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