Tunable Magnetic and Electrical Properties of Cobalt and Zinc Ferrites CO1-XZnXFe2O4 Synthesized by Combustion Route

Co and Zn ferrites with general formula CO1-XZnXFe2O4 (x = 0; 0,2 and 0,8) were synthesized by combustion reaction method, using urea as fuel. The structure of inverse-spinel-type ferrite were characterized through XRD using Rietveld refinement method to identify, quantify phases and determine lattice parameters. The crystallites had mean size of 37,33 nm, 43,66 nm and 51.88 nm with the increment of Zn2+, respectively. Samples were sintered in a resistive oven at 900 °C for 3 hours. Analysis by SEM indicated that the particles have irregular sizes and high concentration of open pores. The magnetic properties were measured using a vibrating sample magnetometer (VSM), through which a decrease in the magnetization variation was observed as the non-magnetic Zn2+ concentration increases. The permittivity and loss tangent were determined using vector network analyzer equipment, permittivity increases with the increase of zinc concentration and the tangent loss measurements were small for all ferrites synthesized in this work.

采用燃烧合成法制备了通式为Co₁₋ₓZnₓFe₂O₄（x取值为0、0.2和0.8）的钴锌铁氧体，以尿素作为燃烧燃料。通过X射线衍射（XRD）结合里特维尔德精修法对反尖晶石型铁氧体的结构进行表征，以完成物相鉴定、定量分析并测定晶格参数。随着非磁性Zn²+掺杂浓度的提升，样品的晶粒平均尺寸分别为37.33 nm、43.66 nm和51.88 nm。将样品置于电阻炉中，于900℃下烧结3小时。扫描电子显微镜（SEM）分析结果表明，颗粒尺寸分布不规则且存在大量开放孔隙。采用振动样品磁强计（VSM）测试样品的磁性能，结果显示随着非磁性Zn²+浓度升高，磁化强度的变化量逐渐降低。通过矢量网络分析仪测定样品的介电常数与损耗角正切值：介电常数随锌掺杂浓度升高而增大，且本研究合成的所有铁氧体样品的损耗角正切值均处于较低水平。