Field-effect switching in nano-graphite films

Abstract

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

Macroscopic-ranged proximity effect in graphite

“…Instead, all our results can be accounted for by considering the pre-existence of superconducting-prone islands in graphite, consistently with previous reports in the literature indicating localized superconducting domains in the material [16,12,14,15,35]. In this context, the presence of superconducting leads can act as a trigger for global coherent transport along such pre-existing channel.…”

“…This can be justified by considering the superconducting islands in graphite as objects with reduced dimensions (as suggested from STM, magnetization and transport measurements in different types of pristine graphite [16,12,14,15,27],…”

“…In addition, indications of SC in this system are scattered across the literature. Among them, are the presence of switching features in magnetoresistance akin to Josephson junction arrays embedded the material [12,13,14,15], signatures of a Bose-metal phase [16,17] (also seen in Bi) and the existence of superconducting-like magnetization hysteresis loops even at high temperatures [17]. In addition, very recently, percolative (R = 0) superconductivity has been measured in twisted bi- [18] and multi-layer [19] graphenes.…”

Nano Graphite Film-Controlled Electrical Switch

“…Хотя переходы «металл -диэлектрик» в графите [26][27] и в неупорядоченном углероде [28][29] хорошо известны, однако до сих пор перехода в состояние диэлектрика в НГ-пленках выше комнатной температуры не обнаружено. Более подробное обсуждение гипотезы сверхпроводимости в НГ-пленках можно найти в работе [30]. Заключение В статье описан вероятный механизм переключения электросопротивления в НГ-пленках.…”

Josephson effect in nanographite films

“…Studies of nanographite films carried out for 30 years [7][8][9][10][11][12] demonstrated the presence of the so-called " weak superconductivity" at room temperature and even higher up to 650 K (Fig. 1).…”