The synthesis, structure and dielectric properties of Bi1.5-xLaxZnNb1.5O7 based ceramics

A series of bismuth-lanthanum-zinc-niobium oxide compositions with the gene ral formulae of Bi1.5-xLaxZnNb1.5O7 (0 less than or equal to x less than or equal to 1.5) were synthesized. A dense and uniform ceramic body was obtai ned in the lower sintering temperatures between 1020 degrees C and 1120 deg rees C. With the aids of XRD analyses, the structure of these compositions was recognized. The dielectric properties were studied, and a dielectric re laxation phenomenon was observed in the intermediate substitutional amounts of lanthanum for bismuth (0.3 less than or equal to x less than or equal t o 1.05). Based on the temperature and frequency dependences of the dielectr ic constants and loss factors, the loosely associated ion interaction treat ed according to Debye Model and the effect of various factors such as chemi cal compositions, processing parameters on the activation energy of ion jum p and the period of atom vibration were discussed.