Amorphous electronic properties

The metal size clearly increases when the decomposition takes place on the substrate. Nevertheless, the overall shift after complete decomposition is the same both on crystalline and amorphous substrates. This can be explained by the assumption that the increase of the number of the metal atoms in the cluster takes place also on an amorphous substrate, on a scale high enough to shift the core levels but low enough to maintain a constant emitted intensity ratio between the substrate and the metal core levels. The authors concluded therefore that the core-level position is highly size-sensitive in the range of very small particles, e.g. < 100 atoms where the associated electronic properties are primarily atomic. However, on approaching the metallic state for >100 atoms, the corelevel shift is a much poorer criterion of the cluster size. 

Metastable amorphous materials can be produced by the rapid quenching of melts in the form of metallic alloys with glassy structures [149]. These materials have attracted the attention of metallurgists, physicists, and, recently, chemists because of their exceptional properties (easy magnetisation, superior corrosion resistance, high mechanical toughness, interesting electronic properties) [150]. The use of these materials in catalysis was reported some years ago [151]. 

Figure 9.2 Temperature history of a CPMD simulation of InP indicating the melting of the crystal into a liquid and the quenching of the liquid into an amorphous solid. [Reprinted by per mission from L. J. Lewis, A. De Vita, and R. Car, Structure and Electronic Properties of Amorphous Indium Phosphide from First Principles, Phys. Rev. B 57 (1998), 1594 (Copyright 1994 by the American Physical Society).]...

L. J. Lewis, A. De Vita, and R. Car, Structure and Electronic Properties of Amorphous Indium Phosphide from First Principles, Phys. Rev. B 57 (1998), 1594. 

Finally, we are convinced that the future development of TSC and TSDC methods as investigative tools of electronic properties of amorphous semiconductors will... 

Flint - [SETCA-AMORPHOUS SILICA] (Vol 21) - [SILICA - INTRODUCTION] (Vol 21) - [CLAYS - USES] (Vol 6) -as abrasive [ABRASIVES] (Vol 1) -ceramics [CERAMICS - ELECTRONIC PROPERTIES AND MATERIAL STRUCTURE] (Vol 5)... 

Since the electronic properties of solids depend on the crystal structure, the transition from the crystalline to the amorphous state is expected to result in some modification of electronic (and surface) properties. Amorphous materials have first been used in catalysis [558-560] where some evidence for higher activity has been obtained [561]. In particular, hydrogenation reactions are catalyzed by this class of materials [562]. Studies on the H recombination reaction are also available [563]. However, the evidence that the amorphous state is really the origin of enhanced catalytic activity is not completely clear [562, 564]. These materials have the peculiarity that their surface is relatively homogeneous for a solid and in particular it is free from grain boundaries [565, 566]. Therefore, they have been suggested [562] as ideal model surfaces for studying elementary catalytic reactions, since they can be prepared with controlled electronic properties and controlled dispersion. Nevertheless, many prob-... 

The electrochemical properties of passive layers lead to the question of their structure on a mesoscopic scale and at atomic resolution. Their barrier character with respect to metal corrosion postulates a dense, poreless film their electronic properties, in some cases, crystalline structures. The change of their properties with film aging, as in e.g. film-breakdown phenomena, support the existence of many defects that may heal with time. In many cases an amorphous structure is assumed. Some ex situ... 

Ma Y, Yang H, Guo J, Sathe C, Agui A, Nordgren J (1998) Structural and Electronic Properties of Low Dielectric Constant Fluorinated Amorphous Carbon Films, Appl Phys Lett 72(25) 3353-3355... 

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