Electrical properties and the structure of glasses in the xNa2O-(1-x)2PbO • B2O3 system

The temperature-concentration dependences of the electrical conductivity and the activation energy for electrical conduction of glasses in the Na2O-B2O3 and Na2O-2PbO (.) B2O3 systems are studied. The investigation into the nature of the electrical conduction in these glasses reveals that the contribution from the electronic component (10(-3)%) of the conductivity is within the sensitivity of the Liang-Wagner technique. A considerable alkali conductivity is observed upon introduction of more than similar to12 mol % Na2O. The true transport number of sodium eta(Na)+ is as large as unity at [Na2O] congruent to 15 mol %. It is shown that the observed temperature-concentration dependences of the electrical and transport properties are governed by the ratio between the concentrations of polar and nonpolar structural-chemical units of the Na+[BO4/2](-), Na+[O-BO2/2] double right arrow Na+[O-BO2/2], Pb-1/2(2+) [BO4/2](-), Pb-1/2(2+) [O-BO2/2], and [BO3/2] types.