Cu离子掺杂对Ni-Zn铁氧体结构和介电性能的影响

摘要

A series of Cu-substituted Ni0.5−xCuxZn0.5Fe2O4 (x=0.12, 0.16, 0.20, 0.24 and 0.28) spinel ferrites were prepared by conventional ceramic method to investigate the effects of Cu compositional variation on the structure and dielectric properties. XRD patterns demonstrate that all the samples are crystallized in single-phase cubic spinel structure and the lattice constant increases with increasing Cu content. White grains observed by SEM are Cu-rich phase. The dielectric constant versus frequency curve displays a normal dielectric behavior of spinel ferrites. While the frequency dependence of dielectric loss tangent is found to be abnormal, exhibiting a peak at certain frequency for all Cu-substituted Ni−Zn ferrites. A maximum of the resistivity is observed atx=0.2 due to the decrease of hopping electrons between Fe2+ and Fe3+ in per unit volume, which is in contrast with the Cu content dependence of dielectric constant and dielectric loss.%通过传统的陶瓷制备工艺制备了一系列Cu掺杂的Ni0.5−xCuxZn0.5Fe2O4(x=0.12,0.16,0.20,0.24,0.28)尖晶石铁氧体，研究Cu离子掺杂对其结构和介电性质的影响。XRD结果表明所有样品均生成了单一的立方尖晶石结构，并且晶格常数随着Cu掺入量的增加而增加。通过扫描电镜观察到位于晶界处的白色颗粒为富Cu相。介电常数随频率变化曲线显示出尖晶石铁氧体典型的介电行为。但介电损耗随频率变化曲线则表现异常，所有的 Cu掺杂Ni−Zn铁氧体样品在某一频率下都表现出损耗峰。由于单位体积内Fe2+/Fe3+之间跃迁的电子数目减少，x=0.2的样品电阻率最大，而介电常数和介电损耗则最小。