Resistive properties of Janson’s point contacts in the conditions of polarization inversion

Abstract

The sensitive element of a new quantum sensor generation is the Janson dendritic point contact. Analytes that are in the space surrounding the sensitive element are able to interact with the freshly formed surface of the conduction channel of the Janson quantum point contact, as well as with the surface of the dendrite during its growth. This interaction provides the influence of the substances under study on the configuration of the output characteristic of the sensor, represented by the system conductivity histogram. The conductivity histogram is built on the basis of the chrono-resistogram of the self-oscillating point-contact cyclic switchover effect, which is directly recorded under self-oscillation conditions. In the structure of the sensor element, Janson's dendritic point contact is immersed in an electrolyte and in an electric field forms a chrono-resistogram, which depends on the environment composition. The paper considers one of the aspects of such chrono-resistograms formation. The features of a gapless electrochemical system in the process of realizing the point-contact cyclic switchover effect are analyzed. Modeling the sensitive element in the form of a gapless electrode system allowed explaining the mechanism and dynamics of the transition “Janson point contact – dendrite and counter electrode in the electrolyte”. The most important parameter of the gapless electrode system is the coordinate of the polarization inversion boundary. It is shown that the idea of the coordinate of the polarization inversion boundary plays a fundamental role in modeling the resistive properties of a point-contact system and its lifetime. The synthesized mathematical models describe well the experimentally obtained dependences of the resistance on the exposure time of the nanostructure in an electric field. It was found that the dependence of the contact resistance on the exposure time, obtained under the assumption of a linear distribution of the anodic polarization along the main axis of the conduction channel, is described by a differential equation in which the growth rate of resistance is directly proportional to the cube of this resistance. The materials obtained make it possible to purposefully optimize the design parameters and operating conditions of sensor devices based on Janson point contacts for the analysis of complex gaseous and liquid mixtures.