锂硼钨酸盐玻璃的分相及其对电性质的影响

Phase Separation in Lithium Borotungstate Glasses and Its Effect on the Electrical Properties

本工作系统研究了 Li_2O-B_2O_3-WO_3系玻璃的分相及其对电性质的影响。研究结果表明,该系有一个很宽的玻璃分相区,并存在二次分相,分相后一相为富硼相,一相为富钨相。观察到微晶在两相界面处形成,说明分相促进了晶化。分相的结果,在碱性区,玻璃的离子电导率提高;在酸性区,玻璃离子电导率稍微降低,而电子导率升高。酸性区复合导电性玻璃分相后介电系数增大,而低频下的电极电容显著降低,主要起因于电子电导率的提高。

In this work,the phase separation in glasses in the Li_2O-B_2O_3-WO_3 system andits effects on electrical properties of glasses are studied.It is found that there is awide liquid-in-liquid phase separation region and exsists second phase separationphenomenon in this system.In phase-separated glasses,the matrix phase is rich inboron oxide and the droplet phase is rich in tungsten oxide.The microcrystallitesare observed to be deposited along the spherical surface of the droplet phase,indica-ting that the phase separation in glasses promotes crystallization.As a result of thephase separation,the ionic conductivity of the ion conductive glasses in the basicarea of the glass-forming region increases and that of the mixed conductive glassesin the acidic area decreases but their electronic conductivity increases,and the diele-ctric constant of the glasses increases,however,the electrode capacitance of the sa-mples at low frequences greatly decreases because of the increased electronic conduc-tivity.