Abstract Mossbauer spectroscopy has long been used to calculate the degree of inversion (λ) in ferrites. To perform this calculation in NiFe2O4, it is assumed that the recoilless f-factors ratio of the Fe3+ cations at octahedral [B] and tetrahedral (A) sites of the spinel structure, f Fe B 3 + f Fe A 3 + , is equal to 1 at very low temperatures and equal to 0.94 at room temperature (RT). However, these values were reported for ideal Fe3O4 but not for NiFe2O4, and the physical properties of both materials are very different. In this work, we use a simple method and propose equations for directly determining the f Fe A 3 + and f Fe B 3 + values at RT relative to the recoilless f-factor of standard metallic iron powder (fFe). NiFe2O4 was synthesized from a stoichiometric mixture of nickel oxide and hematite by combining milling processes and heat treatments. The sample was characterized using X-ray diffraction, Mossbauer spectroscopy, infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and magnetic measurements. The results of all the characterization techniques confirm the synthesis of NiFe2O4 and the formation of the spinel structure. The lattice parameter of the cubic unit cell of NiFe2O4 was calculated using a crystallographic model and the Rietveld refinement. By comparing the lattice parameters, it was possible to determine the degree of inversion (λ = 0.96) of the spinel structure of NiFe2O4, and it could be established that the sample obtained has a mixed spinel structure of the type Ni 0.04 2 + Fe 0.96 3 + A Ni 0.96 2 + Fe 1.04 3 + B O 4 2 - . Finally, a value of f Fe B 3 + f Fe A 3 + = 1.09 ± 0.01 was calculated for NiFe2O4 at RT.

中文翻译：

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计算 NiFe2O4 中穆斯堡尔无后坐力 f 因子的新方法。磁性、形态和结构特性

摘要 穆斯堡尔光谱长期以来一直用于计算铁氧体的反转度 (λ)。为了在 NiFe2O4 中执行此计算，假设尖晶石结构的八面体 [B] 和四面体 (A) 位置处的 Fe3+ 阳离子的无反冲 f 因子比 f Fe B 3 + f Fe A 3 + 相等在非常低的温度下为 1，在室温 (RT) 下为 0.94。然而，这些值是针对理想的 Fe3O4 而不是针对 NiFe2O4 报告的，并且两种材料的物理性质非常不同。在这项工作中，我们使用一种简单的方法并提出了用于直接确定在 RT 下相对于标准金属铁粉 (fFe) 的无后坐力 f 因子的 f Fe A 3 + 和 f Fe B 3 + 值的方程式。NiFe2O4 是由氧化镍和赤铁矿的化学计量混合物通过结合研磨工艺和热处理合成的。使用 X 射线衍射、穆斯堡尔光谱、红外光谱、拉曼光谱、扫描电子显微镜、能量色散 X 射线光谱和磁测量表征样品。所有表征技术的结果证实了 NiFe2O4 的合成和尖晶石结构的形成。NiFe2O4 立方晶胞的晶格参数使用晶体学模型和 Rietveld 精修计算。通过比较晶格参数，可以确定 NiFe2O4 尖晶石结构的反转程度（λ = 0.96），可以确定所得样品具有 Ni 0.04 2 + Fe 0 型混合尖晶石结构. 96 3 + A Ni 0.96 2 + Fe 1.04 3 + BO 4 2 - 。最后，在室温下为 NiFe2O4 计算了 f Fe B 3 + f Fe A 3 + = 1.09 ± 0.01 的值。