Abstract The paper presents the influence of Cu2+ substitution by Co2+ in CuFe2O4 embedded in SiO2 on the structure, morphology and magnetic properties. The CuFe2O4/SiO2, Co0.25Cu0.75Fe2O4/SiO2, Co0.50Cu0.50Fe2O4/SiO2, Co0.75Cu0.25Fe2O4/SiO2 and CoFe2O4/SiO2 nanocomposites (NCs) were obtained by sol-gel method followed by annealing at 500, 800 and 1100 °C. Beside the ferrite, the presence of CuO at low temperature and cristobalite and quartz at high temperature were observed. The size of spherical particles increases from 38 to 85 nm with increasing annealing temperature and Co2+ content. The saturation magnetization, remanent magnetization, coercive field and magnetic anisotropy increase by substituting Cu2+ with Co2+ in the CuFe2O4 structure. The NCs have superparamagnetic and ferromagnetic behavior.

中文翻译：

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Co2+取代Cu2+对溶胶-凝胶法合成CuFe2O4结构和磁性能的影响

摘要 本文研究了嵌入SiO2 中的CuFe2O4 中Cu2+ 被Co2+ 取代对结构、形貌和磁性能的影响。CuFe2O4/SiO2、Co0.25Cu0.75Fe2O4/SiO2、Co0.50Cu0.50Fe2O4/SiO2、Co0.75Cu0.25Fe2O4/SiO2和CoFe2O4/SiO2纳米复合材料（NCs）是通过溶胶-凝胶法获得的，然后在8000℃退火和 1100°C。除铁素体外，还观察到低温下存在 CuO，高温下存在方石英和石英。随着退火温度和 Co2+ 含量的增加，球形颗粒的尺寸从 38 nm 增加到 85 nm。通过在 CuFe2O4 结构中用 Co2+ 取代 Cu2+，饱和磁化强度、剩磁强度、矫顽力和磁各向异性增加。NCs 具有超顺磁性和铁磁性。