Effect of Ba(Y1/2Nb1/2)O3 and BaZrO3 on the cation order and properties of Ba(Co1/3Nb2/3)O3 microwave ceramics

The effector different solid solution additives and heat treatments on the cation order and dielectric properties or Ba(Co1,3Nb23)O-3 (BCoN) were investigated. Pure Ba(Co1/3Nb2,3)O-3 undergoes an order-disorder transition at similar to 1400 degreesC, the Q value of the ordered phase (Q.f = 64,400) is significantly higher than the disordered variant (Q.f = 10,800). The substitution of BaZrO3 destabilizes the 1:2 order and a 1: 1 ordered phase are formed for similar to 10 - 20 mol% BZ. The order-disorder temperatures for the 1: 1 BCoN-BZ phases are quite low (< 1300 <degrees>C) and lead to lower degrees of order and lower: Q values. The substitution of Ba(Y1,2Nb1,2)O-3 (BYN) also induces a transition to 1: 1 ordering, but in this case the stability of the order is significantly higher and the samples remain ordered to at least 1550 degreesC. The greater degree of order in the BYN system is accompanied by a higher Q values compared to their BZ counterparts, however none of the samples reach the Q values of the pure ordered BCoN end-member. (C). 2001 Elsevier Science Ltd. All rights reserved.