CaO掺杂10NiO-NiFe2O4复合陶瓷的导电性能

研究添加剂CaO含量和烧结温度对CaO掺杂10NiO-NiFe2O4复合陶瓷的物相组成和电导率的影响。结果表明:CaO含量在0~4%范围内,烧结试样的X射线衍射谱仅有NiO和NiFe2O4的衍射峰;10NiO-NiFe2O4复合陶瓷在空气中升温过程存在明显的吸氧和失氧行为;CaO含量对1 473 K烧结的10NiO-NiFe2O4复合陶瓷的电导率影响显著;当CaO含量为0~1%时,随测试温度的升高,材料电导率逐渐增大,随后在773~923 K出现1~2个数量级的突降,然后重新缓慢增大;当CaO含量为2%和4%(质量分数,下同)时,材料电导率在298~1 233 K范围内随着测试温度的升高而增大;2?O掺杂10NiO-NiFe2O4复合陶瓷在不同测试温度下均具备最高电导率,1 233 K下达到16.29 S/cm,远高于未掺杂试样的1.03 S/cm;烧结温度由1 473 K提高到1 573 K时,未掺杂试样在1 233 K时电导率提高近15倍,2?O掺杂试样1 233 K时电导率略有提高。

Electrical conductivity of CaO doped 10NiO-NiFe2O4 composite ceramics

The effects of CaO content, in the range from 0% to 4%, and sintering temperature on the phase composition and electrical conductivity of CaO doped 10NiO-NiFe2O4 composite ceramics were studied. The results show that the composites consist of NiO phase and NiFe2O4 phase. There is an apparent oxygen absorbing and releasing behavior during the heating process in air for 10NiO-NiFe2O4 composites. The electrical conductivity of composites sintered at 1 473 K markedly depends on the CaO content. As the CaO content is in the range from 0% to 1%, the conductivity increases firstly with the temperature increasing from room temperature to 773 K, then abruptly decreases with one or two orders of magnitude at the temperature between 773 K and 923 K, and finally increases gently with the temperature increasing from 923 K to 1 233 K. As the CaO content is in the range from 2% to 4%, the conductivity increases with the temperature increasing without a decreasing phenomenon. The maximum conductivity of 16.29 S/cm at 1 233 K is obtained for composites doped with 2?O, compared to the 1.03 S/cm of the undoped composites. As the sintered temperature increases from 1 473 K to 1 573 K, the electrical conductivity at 1 233 K increases about 15 times for the undoped composites, compared to a slight increase for the 2?O doped composites.