【摘要】 研究了Zr4+离子B位置换改性(Pb0.5Ca0.5)(Fe0.5Nb0.5)O3陶瓷微波介电性能。实验结果表明,(Pb0.5Ca0.5)[(Fe0.5Nb0.5)1-yZry]O3(PCFNZ)陶瓷样品呈现单一斜方钙钛矿相结构。随Zr4+离子的置换量增加,PCFNZ陶瓷体系的Qf值和晶粒尺寸逐渐减小;介电常数εr随着置换量增加而提高,这主要是因为Zr4+的离子极化率(αZr=0.325nm)大于(Fe,Nb4)+离子极化率(αB-site=0.313nm)。频率温度系数TCF则随置换量增加开始阶段保持不变,而后急剧减小,由正变负值。当烧结温度为1150℃,Zr4+的置换量在y=0.08时,能够获得优良的微波介电性能:Qf=4938GHz,εr=111,TCF=9.06×10-6/℃。更多还原

【Abstract】 Microwave dielectric properties of B-site substitution by Zr4+ in(Pb0.5Ca0.5)[(Fe0.5Nb0.5)1-yZry]O3(PCFNZ) ceramics were investigated.All specimens that were substituted by Zr4+ were well sintered and single orthorhombic perovskite phase.Qf values and grain sizes of PCFNZ ceramics decreased with the increase of Zr4+ content.The dielectric constant εr increased with the increase of Zr4+ content because of larger ionic polarizability of Zr4+ ion(αZr=0.325nm) than that of(Fe,Nb)4+ ions(αB-site=0.313nm).With the increase of Zr4+ content,the TCF firstly kept almost unchanged,and then drastically decreased from positive to negative.Typically,when Zr4+ content was at y=0.08,the excellent microwave dielectric properties of Qf=4938GHz,εr=111 with TCF=9.06×10-6/℃ were obtained.更多还原