SYNTHESIS AND CHARACTERIZATION OF Bi3Mg2Nb3O14 PYROCHLORE

Abstract

Synthesis of Bi₃Mg₂Nb₃O₁₄ pyrochlore was carried out using conventional solid-state method. Phase formation and electrical properties of Bi₃Mg₂Nb₃O₁₄ pyrochlore were investigated by employment of different instruments. X-ray diffraction technique was applied to analyze the phase purity of the prepared Bi₃Mg₂Nb₃O₁₄ pyrochlore. The surface morphology of Bi₃Mg₂Nb₃O₁₄ pyrochlore was examined by scanning electron microscope. Electrical properties of this sample were studied using ac impedance analyzer, HP4192A in the frequency range of 5 Hz – 13 MHz. The “ideal” Bi₃Mg₂Nb₃O₁₄ formed at 1025°C as cubic pyrochlore with minute traces of secondary phase. The dielectric constant was ~110 at room temperature at 1 MHz. The sample showed negative temperature coefficient of relative permittivity, T_Cε’ ~ -480 ppm/°C in the temperature range of 25 -300°C and low dielectric loss, tan δ, 10-3 at 1 MHz.