Effect of CeO₂ doping on the microscopic morphology and electrical properties of ZnO-based linear resistors

ZnO–MgO–Al₂O₃–TiO₂–SiO₂ linear resistors with different CeO₂ doping were synthesized using the solid-phase synthesis method. The impact of CeO₂ doping on the microstructure and electrical performances of ZnO-based linear resistors were comprehensively discussed. The impedance test results show that the doping of Ce⁴⁺ reduces the grain boundary resistivity from 250.81 kΩ⋅cm to 4.17 kΩ⋅cm, which improves the stability of the resistance. Moreover, the samples exhibited remarkable linear V-I characteristics. When the CeO₂ content was 1.00 mol%, ZnO-based linear resistors have the best linear performance with a nonlinear coefficient α of 1.087 as close as 1. Meanwhile, the sample has a resistivity of 4.17 kΩ⋅cm, and a resistance temperature coefficient α_T of − 5.67 × 10^–3/°C.