Influences of Mg and Mn doping on structure, B-site ordering and microwave dielectric properties of Ba(Co1/3Nb2/3)O3 ceramics

Abstract

Influence of Mg and Mn doping on structure and microwave dielectric properties of Ba(Co _1/3 Nb _2/3 )O _3 (BCN) ceramics with complex perovskite structure is investigated systematically. X-ray diffraction and Raman spectrum investigations show that doping Mg and Mn into BCN ceramics is helpful for improving the quality factor ( Q · f value) resulted from enhanced B-site 1:2 ordering degree. Mg- doped samples show higher ordering degrees and larger Q · f values than Mn- doped counterparts. The sintering density, grain size, 1:2 B-site ordering structure and microwave dielectric properties of BCN ceramics show a strong dependence on Mg and Mn doping content. The sintering density of BCN ceramics can be increased significantly by doping a small amount of Mg and Mn. However, further increase in doping content results in the decrease of sintering density. τ _f value of BCN ceramics can be tailored by doping of Mg into Co sites. The near-zero τ _f value (∼0.64 ppm °C ^−1 ) is obtained when the Mg doping content is at x = 0.1. The ordering degree and Q · f value of Mg- and Mn- doped BCN ceramics increase significantly with increasing annealing time.

Keywords

• microwave ceramics
• doping
• 1:2 ordering degree
• dielectric properties