Processing of Bi 1.5ZnNb 1.5O 7 ceramics for LTCC applications: Comparison of synthesis and sintering methods

Abstract

Bismuth zinc niobate posses a cubic pyrochlore structure and normally is obtained by the conventional solid-state reaction. The great disadvantage of this method is the lack of chemical homogeneity, requiring high synthesis and sintering temperatures (higher than 1000 °C), which is an impeditive for BZN application in LTCC with silver as the internal electrode. The aim of this paper is to compare, from synthesis to sintering, BZN ceramics, derived either from chemically or conventionally synthesized powders, sintered either in both conventional oven for 2 h or microwave oven for 15 min. The results showed that chemically synthesized BZN ceramics sintered in microwave oven at 900 °C for 15 min presented a relative density of 97%, while those obtained by conventional method required 1000 °C to reach the same density. Despite the short period for thermal treatment in microwave oven, the electrical properties of BZN ceramics are compatible with those sintered in conventional oven for 2 h.