A novelty in local electrochemical analysis with a pressing sensor cell (a review)

Abstract

Local electrochemical analysis (LEA) with a pressure cell-sensor (CSC) is based on electrodecrystallization of the material studied (metal, alloy, powder composition, semiconductor structures, etc.) in an area limited by the size of the hole in the graphite CSC filled with the appropriate electrolyte, and recording the dissolution current strength. The selected surface of the analyzed material or product is the working electrode, and the graphite body of the cell or a special electrode inserted into the inert body of the cell is the counter electrode. Choice of the electrolyte and dissolution mode determines the possibility of using LEA with CSC for studying thickness of the layer, surface composition or the distribution of the composition over the thickness of the material layer in the controlled area, with a diameter of 1–2 mm. Design of the CSC and methods of its application were developed in the 60s of the last century by a team of authors from Kuibyshev Polytechnical Institute (now SamSTU) for coulometric control of monolayer metal coatings on watch cases, which resulted in the corresponding requirements to the size of the cell body and its contact hole. Subsequent studies showed possibility of using LEA with CSC for controlling thickness of multilayer metal coatings with individual metals on various products, composition of binary alloy coatings by selective dissolution of their components in a potentiodynamic mode, as well as powders and powder compositions pressed into a pellet electrode, control of the distribution profile of the alloying impurity in silicon epitaxial structures, thickness of oxide films, phase composition of metal alloy samples and a number of other application parameters. The present work provides an overview of advances in the development of theory, methodology, tools and practical applications of local electrochemical analysis over the last decade.