Papers by Keyword: Electrotransport

Abstract: Electric current has a significant effect on the transfer of matter in liquid layers that grow during contact melting. Depending on the direction of the current, both an increase and a decrease in the rate of contact melting can be observed. In this case, the growth of liquid interlayers does not obey the well-known parabolic law, in contrast to the usual (current-less) contact melting in a nonstationary diffusion mode and other diffusion processes. The paper considers the question of the influence of direct electric current on the concentration distribution in the melt formed during contact melting, as well as on the process of movement of interphase boundaries. A solution is obtained for the diffusion equation for a liquid layer growing in the process of contact melting in the presence of a constant electric current in the system. It is shown that the concentration distribution curves and their gradients for the two modes of the process under consideration (accelerating and decelerating) will have a rather different form, while the movement of the interphase boundaries occurs according to a complex law.

Abstract: This study is dedicated to investigating contact melting, including cases of electrotransport is a Sn-Bi system after introduction of a small admixture of indium. It has been shown that the dopant ambiguously influences the rate of the contact melting. The structure of obtained alloys is strongly non-uniform and abounds with dendritic forms. An attempt is made to explain the results.

Abstract: This study is dedicated to application of x-ray methods to investigate phase formation in contact melting in a Cd-In system after introduction of a small admixture of sodium to cadmium, including cases of electrotransport. Formation of both two-and three-component intermetallic compounds has been established. An attempt is made to explain the results.

Abstract: Unmixing of a semiconducting ferrite spinel, (Co0.203Fe0.797)3O4 in an electric field was examined at 1200oC in its disorder regimes of prevailing (cation) vacancies and interstitials, respectively. It has been found that Co becomes enriched at the cathode in the interstitial-prevailing regime and at the anode in the vacancy-prevailing regime, but to much smaller a degree than expected. This confirms that the direction and degree of unmixing is governed by the difference in electrochemical mobility of the competing cations, and the effective charges of the mobile cations are appreciably reduced from their formal ones by the cross effect between the mobile ions and electrons.