【摘要】 通过还原后在空气中热处理氧化的方法制备热敏陶瓷层的高浓度La施主掺杂BaTiO3陶瓷以获得温度热敏半导化陶瓷热敏层。样品在火焰中快速热处理形成半导化层。由于氧空位处于不稳定态,该样品在空气中经过850℃2 h热处理后氧化。与未掺杂Mn的样品比较,掺杂了Mn的样品在比较低的温度下出现PTC效应和具有大的PTC效应。从退火处理的半导化陶瓷层的PTC特性与相同组分陶瓷的介温特性比较看出,相变和氧吸附均是产生PTC效应的主要原因。更多还原

【Abstract】 Heavily La-doped BaTiO3(BT) ceramics were prepared by reduction and then oxidation after heat treat-ment in air for the formation of a thermal sensitive layer.Semiconducting layer was formed by heating and cooling the ceramics rapidly with a lamp heater.Then the ceram-ics were oxidized by annealed in air at 850℃for 2 h due to oxygen vacancy under a unstable state.At a lower an-nealing temperature,a higher PTC effect appeared inMn-doped BT ceramics comparing to the ceramics without Mn-doped.From the comparison between PTC effect for annealed semiconducting ceramic samples and the tem-perature dependence of dielectric constant for the ceram-ics with same composition,it is shown that PTC effect re-sults from the phase transition and the absorption of oxy-gen in grain boundaries.更多还原