Fabrication and Ordering Behavior of Lead Magnesium Niobate Ceramics Doped with Bismuth Cations
ZHAO Chang-Lei; FENG Chu-De(Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China)
The pyrochlore-free Bi_2O_3 doped lead magnesium niobate ceramics were fabricatedthrough columbite precursor method and their B-site ordering structures were characterized byXRD and SAED techniques. With the increase of the ratio between Mg~2+ and Nb~5+ cationcontent, hexagonal Mg_4Nb_9O_6 becomes coexisting with orthorhombic MgNb_2O_6 in the columbiteprecursor. The donor doping with Bi~3+ can compensate for the space charge generated by thenonstoichiometric order and thus promotes the growth of ordering regions. Moreover, the orderingdegree of PMN can be increased pronouncedly with the increase of bismuth cation content of thespecimen. The average size of ordering microdomains estimated in PMN-0.05Bi specimen is about22nm.