The effect of electrical resistivity switching in nano -graphite films is described. In difference with cases published elsewhere the switching in nano -graphite films occurs from stable high conductive to metastable low conductive state. Critical current of switching varies in the range 0.01-0.5A and can be increased up to values appropriate for using of nano -graphite samples in power grids as contact-less current limiters and circuit breakers. The possible mechanisms of switching phenomenon in nano -graphite films are discussed.Physical and electromagnetic properties of the carbon and its derivatives are the subjects of constant interest and extensive studies for many years. Attention has been paid to the switching behavior in the carbon graphite like materials. K. Antonowicz more than 30 years ago investigated the conductive properties of the glassy carbon [1] and its evaporated deposits [2] and has found out the effect of jump of conductivity up to three orders of magnitude. The change of conductivity was reversible, and the relaxation time made some days.B.Z.Jang and L.Zhao also studied the switching behavior of carbonized materials [3]. They study the partially carbonized polyacrylnitride fibbers, which were observed to undergo a resistivity change between 2 and 4 orders of magnitude at a transition temperature typically in the range of 98°C to 200°C. The current-voltage curves exhibited an initial supercurrent-like increase, followed by a rapid drop to a high resistance state, and then a rise in current
The problems of stripper target behavior in the nonstationary intense particle beams are considered. The historical sketch on studies of radiation damage failure of carbon targets under ion bombardment is presented. The simple model of target evaporation under intensive pulsing beam is supposed. Lifetimes of stripper targets under intensive nonstationary beams can be described by two failure mechanisms: radiation damage accumulation and evaporation of a target. At the maximal temperatures less than 2500 K the radiation damage dominates; at temperatures above 2500 K the mechanism of evaporation of a foil prevails. The proposed approach has been applied to the description of stripper foils behavior in Brookhaven National
The satisfactory explanation of abnormal electromagnetics in thin graphite-like carbon films till now is absent. The most comprehensible explanation may be the high-temperature superconductivity (HTSC). Times of spasmodic switching of electrical conductivity are measured in this work in graphite-like nanostructured carbon films, produced by methods of the carbon arc (CA) and chemical vapor deposition (CVD), which have made 1 and 2 nanoseconds correspondingly. So fast switching completely excludes the thermal mechanism of the process. According to HTSC logic, in the time vicinity close to jump of electroresistance it is necessary to expect the generation of optical radiation in infrared (IR) range. This work presents the first results on registration of IR radiation caused by sharp change of conductivity in thin graphite-like carbon films.
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