Microstructures and electric characteristics of SrNdCoO4 ceramics with K2NiF4 structure
SrNdCoO4 ceramics with tetragonal K2NiF4 structure were prepared by a solid-state reaction process. The frequency and temperature dependence of dielectric and conductive properties were studied. A peak was found at ∼325 °C on both dielectric constant (ɛ) and conductivity (σ) plots with temperature. After annealing in O2, the peak of ɛ disappeared while that of σ just shifted a little toward high temperature side. So, some oxide vacancies existed in the polycrystalline SrNdCoO4, which contributed much to ɛ but influenced σ only slightly in the measured temperature and frequency range. A lower resistivity of 3.7 Ωcm was obtained in SrNdCoO4 ceramics sintered at 1150 °C.
KeywordsK2NiF4 Dielectric properties Conductivity Microstructure SrNdCoO4
The present work was supported by Chinese National Key Project for Fundamental Researches under grant No. 2002CB613302, National Science Foundation of China under grant numbers 50272058 and 50332030, and National Science Foundation for Distinguished Young Scholars under grant No. 50025205.
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