Effect of chromium substitution on structural, electrical and magnetic properties of NiZn ferrites  

Cr离子掺杂对NiZn铁氧体结构、电学及磁学性能的影响

作　　者：Guang-sheng LUO Yu-hao HONG Wei-ping ZHOU Zhen-zhi CHENG Chi-cheng MA Zhong-kai WU Huan-huan HUANG 罗广圣;洪宇昊;周卫平;程振之;马驰骋;吴仲楷;黄欢欢(南昌大学材料科学与工程学院,南昌330031;南京大学物理学院固体微结构国家重点实验室,南京210093)

机构地区：[1]School of Materials Science and Engineering,Nanchang University,Nanchang 330031,China [2]National Laboratory of Solid State Microstructures,School of Physics,Nanjing University,Nanjing 210093,China

出　　处：《Transactions of Nonferrous Metals Society of China》2020年第7期1895-1903,共9页中国有色金属学报（英文版）

基　　金：Project(11604147)supported by the National Natural Science Foundation of China;Project(M32048)supported by the Foundation of National Laboratory of Solid State Microstructures,China;Project(20142BBE50014)supported by the Jiangxi Province Key Projects of Science and Technology Support Plan,China。

摘　　要：Ni0.5Zn0.5Fe2-xCrxO4(0≤x≤0.5)ferrites were successfully prepared by conventional solid state reaction method to investigate the effect of chromium substitution on the structural,electrical and magnetic properties.X-ray powder diffraction results demonstrate that all the prepared samples are well crystallized single-phase spinel structures without secondary phase.As chromium concentration increases,the lattice parameter and crystallite size gradually decrease.The magnetic measurement indicates that saturation magnetization is substantially suppressed by Cr3+doping,changing from 73.5 A·m2/kg at x=0 to 46.3 A·m2/kg at x=0.5.While the room-temperature electrical resistivity is more than four orders of magnitude enhanced by Cr3+substitution,reaching up to 1.1×108Ω·cm at x=0.5.The dielectric constant monotonously decreases with rising frequency for these ferrites,showing a normal dielectric dispersion behavior.The compositional dependence of dielectric constant is inverse with that of electrical resistivity,which originates from the reduced Fe2+/Fe3+electric dipole number by doping,indicating inherent correlation between polarization and conduction mechanism in ferrite.通过常规的固相烧结法成功制备Ni0.5Zn0.5Fe2-xCrxO4(0≤x≤0.5)铁氧体,并研究Cr离子掺杂对铁氧体结构、电学及磁学性能的影响。粉末X射线衍射结果表明,所有制备的样品没有杂相,均生成结晶良好的纯尖晶石结构。随着Cr离子掺杂量增加,样品的晶格常数和微晶尺寸逐渐减少。磁性测量结果表明,饱和磁化强度随Cr离子掺杂而大幅度减少,从未掺杂时的73.5 A·m2/kg减少到掺杂比分为0.5时的46.3 A·m2/kg。室温电阻率随着Cr离子的掺杂增加至少4个数量级,在掺杂比分为0.5的样品中达到1.1×108Ω·cm。所有尖晶石样品的介电常数随着频率的增加单调减小,表现出正常的介电色散行为。介电常数随Cr离子掺杂量的变化趋势与电阻率随Cr离子掺杂量的变化趋势相反,掺杂导致Fe2+/Fe3+电偶极子数量减少,表明铁氧体中极化机制和导电机制存在着内在的关联。

关 键 词：NiZn ferrite chromium doping electrical resistivity dielectric properties saturation magnetization 

分 类 号：TM277[一般工业技术—材料科学与工程]