PTCR characteristics of porous (Ba,Sr)TiO3 veramics newly developed by addition of potato-starch

초록

The effect of potato-starch on the PTCR characteristics and microstructure of the porous (Ba,Sr)TiO3 ceramics has been investigated. An addition of 1-20 wt.% potato-starch resulted in the PTCR jump of over 106, which is found 1-2 orders higher than that of the samples without potato-starch. It was found that the porosity largely increased and the grain size slightly decreased with increasing potato-starch, while the crystalline structure of (Ba,Sr)TiO3 ceramics was independent on the potato-starch content. The electrical properties of the (Ba,Sr)TiO3 ceramics have been discussed, based on the results of microstructure, resistivity of grain boundaries, donor concentration of grains and the electrical potential barrier of grain boundaries.