Molecular cluster model of the electronic structure of substitutional impurities in gallium arsenide

1989 ◽  
Vol 1 (6) ◽  
pp. 587-591 ◽  
Author(s):  
Maurizio Casarin ◽  
Andrea Vittadini ◽  
David Ajo ◽  
Gaetano Granozzi ◽  
Eugenio Tondello
1985 ◽  
Vol 46 ◽  
Author(s):  
Jose R. Leite ◽  
Jose L.A. Alves

AbstractThe electronic structures of substitutional and tetrahedral-site interstitial Hg+, Auo and Pt− isoelectronic impurities in silicon have been analysed. The centers are theoretically described by the Watson-sphereterminated molecular cluster model within the framework of the multiplescattering Xa formalism. At the substitutional sites the centers are related to the “vacancy” model recently proposed to describe the properties of the elements at the end of the transition-metal series. At the interstitialsites the impurities introduce a hyperdeep s-like level close to the bottom of the valence band and, in agreement with experiments, do not show shallow donor activities. For all the analysed centers the d-states remain fully occupied below, or within, the valence band.


1993 ◽  
Vol 3 (1) ◽  
pp. 53 ◽  
Author(s):  
Renzo Bertoncello ◽  
Marco Bettinelli ◽  
Maurizio Casarin ◽  
Eugenio Tondello ◽  
Andrea Vittadini

2003 ◽  
Vol 125 (4) ◽  
pp. 687-692 ◽  
Author(s):  
Jung-Yeop Lee ◽  
Hong-Chul Park ◽  
Jung-Yeul Jung ◽  
Ho-Young Kwak

Nucleation temperatures on micro line heaters were measured precisely by obtaining the I-R (current-resistance) characteristic curves of the heaters. The bubble nucleation temperature on the heater with 3 μm width is higher than the superheat limit, while the temperature on the heater with broader width of 5 μm is considerably less than the superheat limit. The nucleation temperatures were also estimated by using the molecular cluster model for bubble nucleation on the cavity free surface with effect of contact angle. The bubble nucleation process was observed by microscope/35 mm camera unit with a flash light of μs duration.


1992 ◽  
Vol 296 ◽  
Author(s):  
Guang Gao ◽  
Ravindra Pandey ◽  
A. Barry Kunz

AbstractAn embedded molecular cluster model is used to study the electronic structure of cyclotrimethylene trinitramine(RDX) molecular crystal. In this model, a molecular cluster describing a local region of the crystal is treated in the Hartree-Fock approximation. The embedding lattice is represented by multipoles that are determined quantum-mechanically. Cluster-lattice orthogonality is achieved by transforming canonical orbitals to orbitals which are localized on individual molecular sites by means of a self-consistent localization potential. Results for the free molecule and the perfect crystal demonstrate the domination of three N-NO2 groups on intermolecular properties. For the defective crystal, results show a significant distortion in the electronic structure caused by local deformations in the lattice that may account for the formation of hot spots.


2019 ◽  
Vol 61 (1) ◽  
pp. 186
Author(s):  
С.Ю. Давыдов

AbstractTwo approaches are proposed to the problem of the coupling of adsorbed particles with atoms of a zigzag edge of graphene formed on a metal substrate. The first approach is based on the Kalkstein and Soven scheme, which makes it possible to determine the electronic structure of a semi-infinite graphene sheet. The second approach is based on a cluster model of a zigzag edge. Analytical expressions are obtained for the local densities of the system’s states and the occupation numbers of a carbon adatom and an adparticle. The case of an isolated adparticle is considered in detail, and a method of taking into account the dipole–dipole interaction of particles aligned along the edge is proposed.


1985 ◽  
Vol 161 (1) ◽  
pp. A542
Author(s):  
Masaru Tsukada ◽  
Chikatoshi Satoko

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