THE EFFECT OF MECHANICAL ACTIVATION OF RARE EARTH ELEMENT OXIDES ON ELECTRICAL RESISTIVITY OF BORATE MELTS

Abstract

The effect of mechanical activation of M2O3 (La2O3, Ce2O3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, Tb2O3, Dy2O3, Ho2O3, Er2O3, Yb2O3, Lu2O3) oxides on the electrical conductivity (ae) of the B2O3–M2O3 molten systems has been studied. It is supposed that protons can be the major current carriers in the melts, which enters the melt because of B2O3 hydration. The ae value change of borate melts for various M2O3 content is explained by the corresponding structure variation of the structural units as a result of dissociation of boron-oxygen groups consisting of OH groups. When temperature grows, the activation energy of electrical conductivity in the B2O3–M2O3 melts increases due to decomposition of superstructural units: [B3O4,5] and B3O3O3/2OH. The dependence of ae value against the serial number of lanthanide in series of B2O3–La2O3 → B2O3–Lu2O3 melts have been found to be subject to the intranuclear periodic sequence, which depends on the stabilization energy of the basic terms of rare earth ions.