Immittance response of CaSnO3 prepared by self-heat-sustained reaction

The potential of CaSnO3 for application as a capacitor component possessing a small temperature coefficient of capacitance has been examined by ac sma ll-signal measurements at elevated temperatures (25-300 degrees C) in the f requency range 5-13 MHz. The samples were synthesized by a novel technique called serf-heat-sustained (SHS) reaction. The ac data were acquired for th e CaSnO3 samples sintered at various temperatures with varying soak tempera tures, T,and some times, t (1200 degrees C less than or equal to T less tha n or equal to 1600 degrees C; 2 h less than or equal to t less than or equa l to 48 h). An analysis of the electrical data in more than one complex-pla ne formalism indicated relaxation processes. The resistance of these sinter ed samples was dominated by the grain boundaries, and the capacitance exhib ited near-linear behavior at elevated temperature for several decades of me asurement frequency. The electrical behavior has been correlated with the e volved microstructure in these samples in conjunction with the results obta ined in a previous study for solid-state reaction (SSR) derived sintered bo dies. The multi-plane analytical criteria provided a meaning for the lumped equivalent circuit representation including the origin and purpose of the contributing elements extracted from each complex plane formalism. (C) 1999 Kluwer Academic Publishers.