Resistivity Versus Geometry Relation In Bulk - Sintered And Thick Film MnCoFe - Oxide Thermistors

  • Obrad S. Aleksić
  • Pantelija M. Nikolić
  • Mirjana N. Simić
  • Verica Ž. Pejović
  • Dana G. Vasiljević-Radović

Abstract

A relation between the electrical resistivity and geometry in bulk (pressed and sintered) and thick film NTC thermistors was determined. A powder mixture consisting of MnO, CoO and Fe2O3 called NTC-3K3 (EI Ferrites) was used for the realization of classical NTC disc shape thermistors sintered at 1200°C /30 min. After that, a thick film NTC thermistor paste was composed using the same powder (0.9 μm particle size on average), 4% of Bi2O3 and an organic vehicle (NTC-3K3-95 /2 EI Iritel). Different thick film thermistor geometry’s were printed of NTC paste on alumina and sintered at 850°C/10 min. PdAg paste was printed on both sintered-bulk and thick film thermistors. Their resistivity vs. geometry was compared. NTC coefficient B was determined on NTC - R (T) curves as B=4200 K. The range of the resistivity values obtained varied for planar shapes from 100 Ω to 10 MΩ, and for classical disc types from 2–200 kΩ

Keywords

Porosity Furnace Ferrite Fe2O3 

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Copyright information

© Springer Science+Business Media New York 1999

Authors and Affiliations

  • Obrad S. Aleksić
    • 1
  • Pantelija M. Nikolić
    • 1
  • Mirjana N. Simić
    • 1
  • Verica Ž. Pejović
    • 1
  • Dana G. Vasiljević-Radović
    • 1
  1. 1.Joint Laboratory for Advanced MaterialsSASABelgradeYugoslavia

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