The present work reports on the synthesis characterization of Ca(Co_1.5-Ni_0.5)Y-type ferrite/GO nanocomposites with 10, 20 and 30 wt% of GO named as C₁, C₂ and C₃, respectively, via ultrasonication technique. The Co-Ni doped Ca-ferrite (Ca₂Co_1.5Ni_0.5Fe₁₂O₂₂) was prepared via sol-gel technique sintered at 900 ^°C for 5 h, and graphene oxide (GO) was prepared by modified Hummer’s method. The structural features and physical properties of the composites were studied by X-ray diffraction, dielectric and electrical measurements. XRD results confirmed the phase formation of Y-type hexaferrite and formation of GO, while the XRD pattern of composites is similar to the pattern of pure Y-type ferrite indicating that restacking of graphene sheets is prevented and ferrite particles are homogenously dispersed on the surface of the graphene oxide sheets. The pure GO exhibits the largest value of dielectric constant (1 × 10⁶) at lower frequency range. The dielectric measurement showed that concentration of GO in composites directly related to dielectric constant. The composite with 30 wt% loading of GO has maximum dielectric constant (25 × 10³) in all composites. It is observed that DC resistivity of composites at room temperature decreased from 12.4 × 10⁸ to 0.96 × 10⁸ ohm-cm with increasing GO concentration. It was observed that resistivity of Y-type ferrite/GO composites decreased with increasing temperature, which indicate the semiconducting nature of composites. The value of activation energy decreased from 0.283 to 0.031 eV with increasing GO concentration in composites, which is consistent with resistivity results.

中文翻译：

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Y型铁氧体增强氧化石墨烯复合材料的合成与表征

本工作通过超声技术报道了_分别以10、20和30 wt％的GO分别命名为C ₁，C ₂和C ₃的Ca（Co _1.5 -Ni _0.5）Y型铁氧体/ GO纳米复合材料的合成表征。。通过溶胶-凝胶技术在900 ^°C下烧结制备了Co-Ni掺杂的Ca铁氧体（Ca ₂ Co _1.5 Ni _0.5 Fe ₁₂ O ₂₂）。 C在5小时后，通过改进的Hummer方法制备氧化石墨烯（GO）。通过X射线衍射，介电和电学测量研究了复合材料的结构特征和物理性能。XRD结果证实了Y型六方铁氧体的相形成和GO的形成，而复合材料的XRD图案类似于纯Y型铁素体的图案，这表明可以防止石墨烯片的再堆积，并且铁素体颗粒均匀地分散在表面上的氧化石墨烯片。纯GO表现出最大的介电常数（1×10 ⁶）在较低的频率范围。介电测量表明，复合材料中GO的浓度与介电常数直接相关。GO负载量为30 wt％的复合材料在所有复合材料中均具有最大介电常数（25×10 ³）。观察到， 随着GO浓度的增加，复合材料在室温下的直流电阻率从12.4×10 ⁸降低至0.96×10 ⁸ ohm-cm。观察到Y型铁氧体/ GO复合材料的电阻率随温度升高而降低，这表明复合材料的半导体性质。随着GO浓度的增加，活化能值从0.283降至0.031 eV，这与电阻率结果一致。