Effects of electron-interface-phonon interactions on interactions between electrons in double-heterostructures

Effects of electron-interface-phonon interaction on the interaction between electrons in double heterostructures are considered. It is found that the interaction potential between electrons caused by each of four interface-phonon modes is different. For electrons moving at the two interfaces of double heterostructure, the interaction energies of the electrons produced by the interaction with antisymmetric modes are positive which indicate that the forces between electrons are repulsive. The interaction energies caused by interaction with symmetric modes are negative and the forces are attractive. The resultant of the forces are attractive and become larger when the width of potential barrier decreases for InAs/GaSb/InAs double heterostructure.     

Cation disordering in Ag2HgI4 and Cu2HgI4

The cation order-disorder transitions in Ag₂HgI₄ and Cu₂HgI₄ are first order. This is unusual, since in other superionic conductors the cation disordering is gradual with temperature if there is no structural phase transition. These two materials are also unique in that they have two disordering cations rather than one. A study of a two species lattice gas model shows that this extra degree of freedom is responsible for the first order nature of this transition on the fcc lattice.     

Downstream Conditions in a Constricted ARC with Radial Injection

The thermal, flow and electrical conditions are presented for the downstream portion of an argon arc with local fluid constriction. The arc is initially wall-stabilized in a 10 mm diameter water-cooled constrictor and at some point after flow becomes fully developed the arc is constricted by a radial inward jet. The redevelopment of the flow downstream of the injection slot is investigated by measurements of the pressure drop, wall heat flux and electric field. It is observed that redevelopment proceeds roughly as predicted by classical theory. Measurements of the electric field indicate that the region of maximum constriction is limited in extent.