Ceramics-Silikáty 60, (2) 122 - 128 (2016)

The sintering behaviors and microwave dielectric properties of BaNd₂Ti₄O₁₂ (BNT4) ceramics with x wt.% MnO₂ dopants (x=0, 1, 2, 3 and 4) were investigated in this paper. The tungsten-bronze type BaNd₂Ti₄O₁₂ accompanied with a certain amount of Ba₂Ti₉O₂₀ secondary phase was observed for all Mn doped compositions when samples were sintered at 1300°C. Manganese substitution for Ti caused a decrease of the lattice parameters, and the addition of MnO₂ effectively improved the densification and lowered the sintering temperature of ceramics, which was closely related to the liquid phase sintering mechanism. The microstructure was homogeneous fine grained when x equaled to 3. At last, the BNT4 with 3.0 wt.% MnO₂ dopants well-sintered at 1300°C for 1h had good microwave dielectric properties of ɛ_r=90.2，Qxf=5225GHz and τ_f=9.7 ppm/°C.