Synthesis and NTC properties of YCr1−xMnxO3 ceramics sintered under nitrogen atmosphere - Archive ouverte HAL
Journal Articles Journal of the European Ceramic Society Year : 2011

Synthesis and NTC properties of YCr1−xMnxO3 ceramics sintered under nitrogen atmosphere

Abstract

YCr1−xMnxO3 (0 ≤ x ≤ 0.8) negative temperature coefficient (NTC) compositions were synthesized by classical solid state reaction at 1200 °C, and sintered under nitrogen atmosphere at 1500 °C and 1600 °C. XRD patterns analysis has revealed that for x ≤ 0.6, the structure consists of a solid solution of an orthorhombic perovskite YCrO3 phase with Mn substitute for Cr. For x ≥ 0.8, a second phase with a structure similar to the hexagonal YMnO3 phase appears. SEM images and calculated open porosity have shown that the substitution of Mn for Cr results in a decrease in porosity. Whatever the sintering temperature, the electrical characterizations (between 25 and 900 °C) have shown that the increase in the manganese content involves the decrease in both resistivity and material constant B (parameter which characterizes the thermal sensitivity of material) when x ≤ 0.6. The magnitude order of the resistivity at 25 °C is of 104–108 Ω cm and activation energies vary from 0.28 to 0.99 eV at low and high temperatures, respectively.

Dates and versions

hal-02150208 , version 1 (07-06-2019)

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Cite

A. Ngueteu Kamlo, J. Bernard, C. Lelievre, D. Houivet. Synthesis and NTC properties of YCr1−xMnxO3 ceramics sintered under nitrogen atmosphere. Journal of the European Ceramic Society, 2011, 31 (8), pp.1457-1463. ⟨10.1016/j.jeurceramsoc.2010.12.025⟩. ⟨hal-02150208⟩
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