Quasi-ballistic, nonequilibrium electron distribution in inhomogeneous semiconductor structures

We report on a study of quasi-ballistic transport in deep submicron, inhomogeneous semiconductor structures, focusing on the analysis of signatures found in the full nonequilibrium electron distribution. We perform self-consistent numerical calculations of the Poisson-Boltzmann equations for a model n(+)-n(-)-n(+) GaAs structure and realistic, energy-dependent scattering. We show that, in general, the electron distribution displays significant, temperature dependent broadening and pronounced structure in the high-velocity tail of the distribution. The observed characteristics have a strong spatial dependence, related to the energy-dependence of the scattering, and the large inhomogeneous electric field variations in these systems. We show that in this quasi-ballistic regime, the high-velocity tail structure is due to pure ballistic transport, whereas the strong broadening is due to electron scattering within the channel, and at the source(drain) interfaces.Comment: 4 pages, 2 figure

Study of an Oscillator with Two Degrees of Freedom by a Differential Analyser

Equations giving the stable amplitudes of oscillation and the conditions of stability of nil the possible modes of oscillation of an oscillator with two degrees of freedom and stabilised by a non-linearity which can be described by a third degree polynomial are given, The use of a differential analyser for the verification of these equations is illustrated. Also a method of graphically representing the transient oscillations on the analyser is described

Differential scanning calorimetric studies of several compounds showing order-disorder transition

Differential scanning calorimetric measurements have been carried out for Cul, CuBr, Agl, Ag2S, NaNO2, NaNO3 and KSCN. First-order phase transformations occur with the compounds Cul, CuBr, Agl and Ag2S; NaNO2, NaNO3 and KSCN exhibit λ-type transformations. The enthalpy changes due to phase transitions have been determined. Thermal hysteresis exhibited by these compounds have been examined in the light of their change in unit cell volumes