The Effect of the Mixing Condition on the Microstructure and Electrical Properties of a Glass Composite Containing Semiconductive SnO2 Fine Particles Prepared by a Mechano-chemical Process

Haruhisa SHIOMI, Tomohisa GOTO, Masahiko NAKAMURA
1998 Journal of the Society of Powder Technology Japan  
This study was undertaken to clarify the effect of the mixing condition of SnO2 and glass partieles on the densification behavior, the microstructure and the electrical properties of the glass composites containing semiconductive SnO2 particles prepared by a mechano -chemical process. The relationship between the electrical properties of the glass composites and the dispersion state of the SnO2 particles in a glass matrix was discussed based on the results of the quantitative analysis of SnO2
more » ... rticle dispersion by the computer-assisted image analysis of SEM photographs. The results are summarized as follows: (1) The homogeneity of the mixing state of SnO2 and glass particles mainly depends on the degree of pulverization of the glass particles because the SnO2 aggregates formed during the mechanochemical synthesis of the SnO2 -Sb2O3 powder mixture are easily disintegrated during ball or attrition -milling. Therefore, when the mixing condition in which glass particles are effectively pulverized, such as in attrition milling, is applied, homogeneous mixing is easily achieved, and densely sintered glass composites with homogeneously dispersed SnO2 particles are obtained at low firing temperatures. (2) The electrical conductivity and the temperature coefficient of resistivity (TCR) of the glass composites fired at low temperatures largely depend on the degree of densification. The glass composites well densified at low firing temperatures, such as an attrition-milled sample, show a high electrical conductivity and a small negative TCR at low firing temperatures. On the other hand, the electrical conductivity and TCR of the glass composites fired at high temperatures are significantly influenced by the SnO2 particle dispersion in a glass matrix. When comparing the densely sintered glass composites, the electrical conductivity becomes higher, and TCR approaches zero when the highly aggregated SnO2 particles form networks in the glass matrix.
doi:10.4164/sptj.35.360 fatcat:egtcoktqbjeplnzdmha4cwvidy