Phase change and electrical resistivity of Zn–Mn–Ni–O-based NTC thermistors produced using IZC powder recycled from used dry batteries

• Published in: Ceramics international 2008-05, Vol.34 (4), p.853-857
• Main Authors: Takahashi, J., Miura, A., Itoh, H., Sawayama, K., Akazawa, T., Nebuka, K., Miura, H., Kishi, M.
• Format: Article
• Language: English
• Subjects: A. Sintering; Applied sciences; C. Electrical conductivity; D. Spinels; E. Thermistors; Electronics; Exact sciences and technology; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Thermoelectric, pyroelectric devices, etc
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2007.09.035

Zn–Mn–Ni–Oxide-based NTC thermistors with variable Ni/Mn ratios were fabricated from powder mixtures of recycled IZC, and commercial MnCO 3 and NiCO 3. Solid phases and electrical resistivity of each sintered sample were studied as a function of Ni/Mn ratio, sintering temperature and sintering time. At 1200 °C for 2 h, samples with the Ni/Mn ratios of 0.38 and higher were found to consist of cubic spinel as a major phase. After sintering at 1250 °C for 10 h, densification proceeded with a phase change from cubic spinel to tetragonal one. The electrical resistivity of the samples obtained at 1200 °C for 2 h progressively decreased with an increasing Ni/Mn ratio up to 0.38, at which the value became the lowest (4.2 × 10 3 Ω cm at room temperature) of all the samples fabricated.