Effect of percolation path on temperature dependence of threshold voltage variability in bulk MOSFETs

Threshold voltage variability of bulk MOSFETs was measured at room temperature and cryogenic temperature and compared. It is found that the temperature dependences of threshold voltage defined by extrapolation (VTHEX) and threshold voltage defined by constant current (VTHC) show different behaviors and the percolation path in the channel, which is caused by potential valley due to random dopant fluctuations, weakens the temperature dependence of VTHC.

Optimal planning of networks of mobile objects under uncertainty

When solving a given common task, a swarm of moving objects coordinates the state of its individual members. When planning swarm operations, there is a need to take into account the possibility of its operational regrouping, since at the time of planning the exact purpose of the swarm operation may be either not yet defined, or secret, or determined by a number of random circumstances. At the same time, the swarm resources are insufficient for one-time coverage of all possible targets in a given service area. Therefore, the execution of the operation of the swarm begins to resolve the aforementioned uncertainties. In this case, the operation time can be significantly reduced. This problem is solved by methods of the percolation theory. A concept of programmable percolation of the service area, which is implemented in two phases, is introduced. The value of the concentration of objects in a basic stochastic swarm is obtained numerically -- using the results of statistical modeling of two-phase operations -- and analytically, providing a minimum total cost of the two-phase operation. The synergy of information interaction between the swarm objects when implementing a programmable percolation path is analyzed.

Electrical characterization of aeronautical nanocomposites supported by Tunneling AFM (TUNA)

Epoxy nanocomposites fulfill tight and compelling industrial requirements in the field of structural material for aeronautical applications. In this paper the development and characterization of nanocomposites obtained by filling tetrafunctional epoxy resin (tetraglycidyl methylene dianiline cured with the aromatic diamine 4,4’-diaminodiphenylsulfone, named T20BD) with carbon nanofibers (CNF) is discussed. A filler amount ranging from 0.05% to 2%wt is considered. The DC volume conductivity and the dielectric characteristics (ϵ’) of the nanocomposites in the frequency range 100Hz-1MHz are analyzed and compared with those of the pure resin. Atomic force microscopy, mapping the local topography by means of tunneling effect, is used for recording the electrical percolation path for nanocomposites. In particular, the case 1.3wt% of CNF filled nanocomposites that exhibits a stable behavior of the conductivity in the full investigated frequency range, is here reported. The developed filled epoxy used in carbon fiber reinforced composites, shows enhanced electrical properties leading to better electromagnetic (EM) performances in EM coatings, EM shields and filters or radar absorber materials (RAMs).

Evolution of I-V Characteristics and Photo Effects of Heterojunction LBMO/ZnO Prepared by IBS

The hetero p-n junctions of LBMO/ZnO were fabricated by ion beam sputtering. The sample shows clear temperature-dependent rectifying current (I)-voltage (V) characteristics, and junction resistance vs temperature curve is reflected by the CMR nature based on DEC model. The sample shows two-step switching, then theI-Vis composed of very-low-resistance (VLR), low-resistance (LR) and high-resistance (HR) regions. The wholeI-Vbehavior is changed by measurement running current. The switching is caused by the spot current, and the original VLR is restored when the current is reduced. The mechanism of switching is proposed in terms of the percolation paths composed of metallic FM-grains. Photo illumination effect on theI-Vwas investigated. The currents are increased in VLR and HR regions by the illumination. Two origins are possible, electronic process due to hole injection, and phase process. The percolation path might be reinforced by the light.