【摘要】 通过常规的固相烧结法成功制备Ni_0.5Zn_0.5Fe_2-xCr_xO₄（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。更多还原

【Abstract】 Ni_0.5Zn_0.5Fe_2-xCr_xO₄（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.更多还原