Ni_(2)O_(3)和ZrO_(2)共掺杂CaCu_(3)Ti_(4)O_(12)陶瓷的介电性能研究

Dielectric properties of CaCu_(3)Ti_(4)O_(12)ceramics co-doped with Ni_(2)O_(3)and ZrO_(2)

CaCu_(3)Ti_(4)O_(12)(CCTO)介电陶瓷因具有极高的介电常数(ε′)而受到了广泛的关注与研究,并在电容器材料领域展现出巨大潜力。然而,较高的介电损耗(tanδ)和较差的温度稳定性限制了其发展。为了降低CCTO陶瓷的tanδ并提高温度稳定性,通过溶胶-凝胶法制备了Ni_(2)O_(3)和ZrO_(2)共掺杂的CCTO陶瓷。研究发现:通过掺杂Ni_(2)O_(3)和ZrO_(2),样品在维持高ε′的同时,显著地提高了温度稳定性并降低了tanδ。特别是质量分数1%Ni_(2)O_(3)和1%ZrO_(2)共掺杂的样品,其ε′高达4710,在-125~200℃温度范围内变化小于±20%,符合X9S电容器的标准(在-55~200℃范围内,Δε′<±20%)。并且该样品在室温下的tanδ低至0.012,优于纯CCTO的0.025。这些优异的性能与较大的晶界活化能和较高的晶界电阻有着密不可分的关系。

CaCu_(3)Ti_(4)O_(12)(CCTO)dielectric ceramics have attracted widespread attention and research interest owing to their extremely high dielectric constant(ε′),which shows significant potential in the capacitor materials field.However,the development has been hampered by the elevated dielectric loss(tanδ)and inadequate temperature stability of it.In order to mitigate tanδand enhance temperature stability of the ceramics,CCTO ceramics co-doped with Ni_(2)O_(3)and ZrO_(2)were synthesized via sol-gel method.The investigation reveals that,with the doping of Ni_(2)O_(3) and ZrO_(2),highε′of the ceramic is maintained,while the temperature stability is substantially improved and tanδis reduced.It should be noted that the samples co-doped with 1%Ni_(2)O_(3) and 1%ZrO_(2)exhibits anε′as high as 4710,with variations within±20%across the temperature range from-125 to 200℃,which conforms to the standards of X9S capacitors(Δε′<±20%)within the range from-55 to 200℃.Furthermore,the tanδof this sample at room temperature is lower than that of pure CCTO(0.012 compared to 0.025).These outstanding performances are closely associated with the increased grain boundary activation energy and grain boundary resistance.