Termolecular chemical reactions: Recombination of atomic hydrogen

1974 ◽  
Vol 11 (3) ◽  
pp. 187-191 ◽  
Author(s):  
R. E. Mlckens
1989 ◽  
Vol 149 ◽  
Author(s):  
M Azuma ◽  
H Shirai ◽  
J. Hanna ◽  
I Shimizu

ABSTRACTChemical reactions were systematically investigated with regard to the propagation of Si-network in the vicinity of the growing surface by using various precursors, SiHn, SiHnFm, and SiHnCim (n+m≤3) generated by plasma-induced decomposition of SiH4, SiF4, SiH2Cl2 and SiHCl3. Atomic hydrogen was an effective agent to promote the propagation reaction due to its strong chemical affinity for silicon and its ability to diffuse through the Si-network. A preliminary analysis was made of the kinetics of the propagation reactions.


2005 ◽  
Vol 66 (2-4) ◽  
pp. 513-520 ◽  
Author(s):  
V.V. Styrov ◽  
V.I. Tyutyunnikov ◽  
O.T. Sergeev ◽  
Y. Oya ◽  
K. Okuno

1989 ◽  
Vol 164 ◽  
Author(s):  
Isamu Shimizu ◽  
Jun-Ichi Hanna ◽  
Hajime Shirai

AbstractA systematic study has been made on the formation of Si-network of amorphous(a-), microcrystalline(μc-) and epitaxial (epi)-Si prepared by Plasma-Enhaced (PE-) CVD under control of flow of atomic hydrogen. The control of the Si-network structures requires a deliberate selection of the precursor, i.e., SiHn (n≤53) and SiFnHm (n+m≤53), as well as an intentional acceleration of the chemical reactions for the propagation of Si-network in the vicinity of the growing surface by impinging of atomic hydrogen. A plausible interpretation was given to the growing mechanism of c-Si at low temperature.


Author(s):  
H.H. Rotermund

Chemical reactions at a surface will in most cases show a measurable influence on the work function of the clean surface. This change of the work function δφ can be used to image the local distributions of the investigated reaction,.if one of the reacting partners is adsorbed at the surface in form of islands of sufficient size (Δ>0.2μm). These can than be visualized via a photoemission electron microscope (PEEM). Changes of φ as low as 2 meV give already a change in the total intensity of a PEEM picture. To achieve reasonable contrast for an image several 10 meV of δφ are needed. Dynamic processes as surface diffusion of CO or O on single crystal surfaces as well as reaction / diffusion fronts have been observed in real time and space.


Author(s):  
Anthony S-Y Leong ◽  
David W Gove

Microwaves (MW) are electromagnetic waves which are commonly generated at a frequency of 2.45 GHz. When dipolar molecules such as water, the polar side chains of proteins and other molecules with an uneven distribution of electrical charge are exposed to such non-ionizing radiation, they oscillate through 180° at a rate of 2,450 million cycles/s. This rapid kinetic movement results in accelerated chemical reactions and produces instantaneous heat. MWs have recently been applied to a wide range of procedures for light microscopy. MWs generated by domestic ovens have been used as a primary method of tissue fixation, it has been applied to the various stages of tissue processing as well as to a wide variety of staining procedures. This use of MWs has not only resulted in drastic reductions in the time required for tissue fixation, processing and staining, but have also produced better cytologic images in cryostat sections, and more importantly, have resulted in better preservation of cellular antigens.


Author(s):  
David R. Veblen

Extended defects and interfaces control many processes in rock-forming minerals, from chemical reactions to rock deformation. In many cases, it is not the average structure of a defect or interface that is most important, but rather the structure of defect terminations or offsets in an interface. One of the major thrusts of high-resolution electron microscopy in the earth sciences has been to identify the role of defect fine structures in reactions and to determine the structures of such features. This paper will review studies using HREM and image simulations to determine the structures of defects in silicate and oxide minerals and present several examples of the role of defects in mineral chemical reactions. In some cases, the geological occurrence can be used to constrain the diffusional properties of defects.The simplest reactions in minerals involve exsolution (precipitation) of one mineral from another with a similar crystal structure, and pyroxenes (single-chain silicates) provide a good example. Although conventional TEM studies have led to a basic understanding of this sort of phase separation in pyroxenes via spinodal decomposition or nucleation and growth, HREM has provided a much more detailed appreciation of the processes involved.


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