Topic
Amorphous solid
About: Amorphous solid is a research topic. Over the lifetime, 117050 publications have been published within this topic receiving 2267692 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this paper, a linear temperature dependence of the specific heat in amorphous solids at very low temperatures is shown to follow from an ionic tunneling model, which predicts both the observed temperature dependence and the magnitude of the thermal conductivity.
Abstract: A linear temperature dependence of the specific heat in amorphous solids at very low temperatures is shown to follow from an ionic tunneling model. Moreover, this model predicts both the observed temperature dependence and the magnitude of the thermal conductivity and also explains the anomalous results obtained for the phonon free path by means of stimulated Brillouin scattering.
1,953 citations
TL;DR: The glass-forming tendency of a given material is determined principally by a set of factors which can be specified to some extent in the laboratory, namely, the cooling rate, - T, the liquid volume, v], and the seed density, ps and depending upon the materials constants: the reduced crystal-liquid interfacial tension, α the fraction, f, of acceptor sites in the crystal surface, and the reduced glass temperature, Trg.
Abstract: Summary Generally substances are more stable in a crystalline than in a glassy state. Therefore, to form a glass, crystallization must be bypassed. Under certain conditions, the melts of many substances can be cooled to the glass state. Whether or not the melt of a given material forms a glass is determined principally by a set of factors which can be specified to some extent in the laboratory, namely, the cooling rate, - T, the liquid volume, v], and the seed density, ps and upon a set of materials constants: the reduced crystal–liquid interfacial tension, α the fraction, f, of acceptor sites in the crystal surface, and the reduced glass temperature, Trg . The glass-forming tendency will be greater the larger are - T and Trg and the smaller are v]. ps, and f. The number and variety of substances which have been prepared in a glassy or ‘amorphous solid’ form have been greatly increased with techniques in which the material is condensed from solution on to a surface held well below its glass temperature. T...
1,896 citations
TL;DR: In this article, a comprehensive survey is given of the experimental a.c. data for two types of amorphous semiconductor, namely chalcogenide and pnictide materials, and it is concluded that the behavior at intermediate to high temperatures is well accounted for by the correlated-barrier-hopping model, whereas the low-temperature behaviour is probably due to atomic tunnelling.
Abstract: The various origins of a frequency-dependent conductivity in amorphous semiconductors are reviewed, stressing particularly recent advances and the influences that factors such as correlation and non-random spatial distributions of electrically active centres can have on the a.c. conductivity. A comprehensive survey is given of the experimental a.c. data for two types of amorphous semiconductor, namely chalcogenide and pnictide materials. It is concluded that the a.c. behaviour at intermediate to high temperatures is well accounted for by the correlated-barrier-hopping model, whereas the low-temperature behaviour is probably due to atomic tunnelling.
1,814 citations
TL;DR: In this article, the formation of equivalent stable structures in the layered semiconductor tungsten disulphide was reported, and the closed nature of the structures was verified by electron diffraction and lattice imaging.
Abstract: FOLLOWING the discovery of C60(ref. 1) and the advent of fullerene chemistry, considerable attention has been directed towards the associated cylindrical2,3 and polyhedral4,5 forms of graphite. To date, however, observations of such closed structures have been limited to the carbon system. Here we report the formation of equivalent stable structures in the layered semiconductor tungsten disulphide. After the heating of thin tungsten films in an atmosphere of hydrogen sulphide, transmission electron microscopy reveals a variety of concentric polyhedral and cylindrical structures (ranging in size from 100 nm) growing from the amorphous tungsten matrix. The closed nature of the structures is verified by electron diffraction and lattice imaging. As with the carbon system, complete closure of the tungsten disulphide layers requires the presence of structural defects (for example, edge dislocations), or the arrangement of atoms in polyhedra other than a planar hexagonal geometry.
1,813 citations
TL;DR: An ac technique for measuring the thermal conductivity of dielectric solids between 30 and 750 K is described in this article, which can be applied to bulk amorphous solids and crystals.
Abstract: An ac technique for measuring the thermal conductivity of dielectric solids between 30 and 750 K is described This technique, the 3ω method, can be applied to bulk amorphous solids and crystals as well as amorphous films tens of microns thick Errors from black‐body radiation are calculated to be less than 2% even at 1000 K Data for a‐SiO2, Pyrex 7740, and Pyroceram 9606 are compared to results obtained by conventional techniques
1,729 citations