title: Co and Fe doping effect on negative temperature coefficient characteristics of nano-grained NiMn2O4 thick films fabricated by aerosol-deposition.
abstract: Spinel structured highly dense NiMn2O4-based (NMO) negative temperature coefficient (NTC) thermistor thick films were fabricated by aerosol-deposition at room temperature. To enhance the thermistor B constant, which represents the temperature sensitivity of the NMO thermistor material, Co and Co-Fe doping was applied. In the case of single element doping of Co, 5 mol% doped NMO showed a high B constant of over 5000 K, while undoped NMO showed -4000 K. By doping Fe to the 5 mol% Co doped NMO, the B constant was more enhanced at over 5600 K. The aging effect on the NTC characteristics of Co doped and Fe-Co co-doped NMO thick film showed very stable resistivity-time characteristics because of the highly dense microstructure.
authors.affiliation: Functional Ceramics Research Group, Korea Institute of Materials Science (KIMS), Changwon, Gyeongnam 641-831, Korea.
authors.forename: Jungho
authors.initials: J
authors.lastname: Ryu
authors.forename: Guifang
authors.initials: G
authors.lastname: Han
authors.forename: Jong-Pil
authors.initials: JP
authors.lastname: Lee
authors.forename: Dong-Soo
authors.initials: DS
authors.lastname: Lim
authors.forename: Yun-Soo
authors.initials: YS
authors.lastname: Park
authors.forename: Dae-Yong
authors.initials: DY
authors.lastname: Jeong
mesh_terms: D000336:Aerosols / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D006358:Hot Temperature; D007501:Iron / Q000737:chemistry*; D008422:Materials Testing; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D008968:Molecular Conformation; D010316:Particle Size; D013499:Surface Properties; D013814:Thermal Conductivity
chemical_list: D000336:Aerosols; D008567:Membranes, Artificial; D003035:Cobalt; D007501:Iron