Preparation and electrical characterization of a new linear negative temperature coefficient (1−x)BaSn0.96Sb0.04O3–xCoFe0.5Co1.5O4 composite ceramics

(1− x )BaSn 0.96 Sb 0.04 O 3 – x CoFe 0.5 Co 1.5 O 4 ( x =0.1, 0.3, 0.5, 0.7 and 0.9) composite ceramics had been fabricated through conventional solid-state method. The X-ray diffraction analysis indicated that the composite ceramics consisted of two phases: a perovskite BaSn 0.96 Sb 0.04 O 3 phase and a cubic spinel CoFe 0.5 Co 1.5 O 4 phase. The composite ceramics were more dense and lower porosity with increasing the CoFe 0.5 Co 1.5 O 4 content by SEM. The obtained ρ 25 and B 25/50 constants and activation energy of the composite ceramics were in the range of 1.61×10 5 –1.06×10 6   Ω   cm, 1048–8458   K and 0.09–0.729   eV, respectively. In particular, their relationship between R and T which differed from normal NTC displayed a good linear characteristic at 0–200   °C. It could be used expediently in digital instrument and precision measurement.