| Bi2(Zn1/3Nb2/32O7(β-BZN) materials is the monocline pyrochlore structure have been paid more and more attention for very low losses and high dielectric constant in microwave device applications. Bi2(Zn1/3Nb2/32O7 ceramics were prepared by a solid phase reaction method, The effect of A-site and (A, B)-site substitution on dielectric properties of BZN ceramics was investigated. The effect of oxygen vacancies on dielectric properties of BZN ceramics, sintering temperature, the phase transition and mechanism of modification, especially learned the rule of the shift of relaxation peak temperature with the change of substitution were studied. These provide a experimental basis for further exploration of dielectric relaxation mechanism. The chief result as following:(1) (Bi2-xLix)(Zn1/3Nb2/32O7 ceramics were prepared by a solid phase reaction method. (Bi2-xLix)(Zn1/3Nb2/3)2O7 ceramics have single monocline pyrochlore phase by XRD when 0c) of dielectric constant increases firstly, then it decreases.(2) The (Bi1.975Li0.025)(Zn1/3Nb2/3-x/2Mx/2)2O7)M=(Zr,Sn,Ti) microwave ceramics are prepared by traditional solid phase reaction, The effect of (Zr4+,Sn4+,Ti4+) which radius decreases substitution for Nb5+ dielectric properties of BLZNM based ceramics are investigated. It is discovered that a shift of the relaxation peak for the dielectric loss is obviously observed. The difference in the temperature peaks of dielectric relaxation and the asymmetry of dielectric relaxation was analyzed.(3) The effects of substitution of Li+ for Bi3+ on dielectric properties of (Bi2-xLix)(Zn2/3Nb1.1833Zr0.15)O7 and (Bi2-xLix)(Zn2/3Nb1.1833Sn0.15)O7 ceramics were investigated. the peak of dielectric constant relaxation of Li+,Zr4+ substituted sample moved towards high-temperature with the increasing of substituted content (from 0.025 to 0.1). When x was increased from 0.025 to 0.05 and 0.075 and then 0.1, the peak temperatures of (Li-Sn)-doped samples were from 5℃to 85℃, 100℃and to 92℃, respectively.(4) The effects of substitution of (Cu2+,Al3+,V5+,Mo6+) for Nb5+ on dielectric properties of (Bi1.975Li0.025)(Zn2/3Nb4/3-xMx)O7 ceramics were investigated. It is discovered that a shift of the relaxation peak for the dielectric loss is obviously observed on (Li-Cu)-doped samples and (Li-V)-doped samples and (Li-Mo)-doped samples. The lattice constant ratio (c/a) decreases as x increases on (Li-V)-doped samples, A shift of the relaxation peak to low temperature was caused by activation energy decreasing.
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