Structure, synthesis and high dielectric property of (NaBi)(NbCr)O_6 pyrochlores

摘要

Pyrochlores with composition (NaBi)(NbCr)O_6 were sintered in the temperature range of 1100-1250 deg C. Dielectric properties of the ceramics were investigated in a wide range of temperatures of -15 to 200 deg C and frequencies of 1-800 kHz. The suitable sintering temperatures for (NaBi)(NbCr)O_6 ceramics are suggested from 1150 to 1200 deg C. The dielectric constant behavior reflects, in our opinion, the formation of the space charge and the orientational polarization. The pyrochlores have convex resistivity-temperature characteristics around the transition point, and exhibit the negative temperature coefficient of resistance characteristics. The activation energies of conductivity of samples were obtained at various sintering temperatures.