Rare‐earth ions doped Ca_0.9R_0.1CeNbMoO₈ (R = Y, Sm, Nd, La) ceramics have been successfully prepared by solid‐state method, and their modifications to the microstructure and electrical properties are also investigated. The rare‐earth ions doped ceramics exhibit the scheelite structure. With the increase in the radius of rare‐earth ions, the lattice distortion and bond interaction will be enhanced, and the consistency of grain size will be reduced. The ceramics exhibit negative temperature coefficient (NTC) thermistor characteristics in the temperature range of 473 K‐1273 K, and the activation energy decreases with the increase of the radius of rare‐earth ions. Rare‐earth ions doping can increase the content of Ce³⁺ ions and promote the conductivity of ceramics. Except for Sm³⁺‐doped ceramics, the high‐temperature aging rate of other ceramics is less than 2%. The existence of some metastable Sm²⁺ ions in Sm³⁺‐doped ceramics not only increases the activation energy, but also reduces the high‐temperature stability of the ceramics.

中文翻译：

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稀土离子掺杂引起的Ca0.9R0.1CeNbMoO8（R = Y，Sm，Nd，La）陶瓷的微观结构和电学变化

稀土离子掺杂的Ca _0.9 R _0.1 CeNbMoO ₈（R  = Y，Sm，Nd，La）陶瓷已通过固态方法成功制备，并研究了它们对微观结构和电性能的影响。稀土离子掺杂陶瓷具有白钨矿结构。随着稀土离子半径的增加，晶格畸变和键相互作用将增强，并且晶粒尺寸的一致性将降低。陶瓷在473 K-1273 K的温度范围内表现出负温度系数（NTC）热敏电阻特性，并且活化能随着稀土离子半径的增加而降低。稀土离子掺杂可增加Ce ³⁺的含量离子并促进陶瓷的导电性。除掺有Sm ^3+的陶瓷外，其他陶瓷的高温老化率均低于2％。掺Sm ^3+的陶瓷中存在一些亚稳态Sm ²⁺离子，不仅增加了活化能，而且降低了陶瓷的高温稳定性。