Phase equilibria, thermodynamic analysis and electrical properties of the Li2O-Y2O3-B2O3 system

Phase equilibria in the Li2O-Y2O3-B2O3 system are studied via the methods of thermodynamic, differential thermal analysis and X-ray diffractometry. The physico-chemical characteristics of the previously mentioned intermediate compounds with the compositions 2Li(2)O center dot Y2O3 center dot 5B(2)O(3), 6Li(2)O center dot Y2O3 center dot 3B(2)O(3), 3Li(2)O center dot 2Y(2)O(3)center dot 3B(2)O(3) are clarified. T-x diagrams of polythermal sections, isothermal section at 25 degrees C, and liquidus surface projection for the Li2O-Y2O3-B2O3 system were constructed. The temperature dependencies for electrical conductivity of compounds of the Li2O-Y2O3-B2O3 system are studied. It has been shown that the conductivity of these compounds in polycrystalline form exponentially increases with increasing temperature. This indicates the semiconductor nature of the conductivity of the studied samples. The activation energies of the conductivity for these samples are determined. (C) 2020 Elsevier B.V. All rights reserved.