Cr3+ ion-doped Ni–Ba–Co ferrite with the chemical formula Ni0.2Ba0.1Co0.7Fe2-xCrxO4 was prepared by the sol–gel route. The X-ray diffraction analysis confirmed spinel-phase structure of the prepared Cr3+ ion-doped Ni–Ba–Co ferrite. By Scherrer’s formula, the average crystallite size was calculated. Meanwhile, from Fourier transform infrared spectroscopy, the absorption peaks around 590 cm− 1 were found; it can be inferred that the prepared samples had spinel structure. Transmission electron microscopy images showed that the prepared particles had spherical cube shape and were in the nanosize range. EDS analyzed the elements and ingredients of samples. Vibrating sample magnetometer results revealed that the values of Ms, Mr and Hc increased with Cr3+ ions doping level from 0 to 0.075; when x = 0.1, the above three slightly decreased. This indicates that proper doping content can enhance the magnetic properties. The material can be used for audio, videotape and high-density digital recording disk in information storage industry.

中文翻译：

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Cr3+ 离子掺杂 Ni-Ba-Co 铁氧体的结构和磁性研究

化学式为 Ni0.2Ba0.1Co0.7Fe2-xCrxO4 的 Cr3+ 离子掺杂 Ni-Ba-Co 铁氧体是通过溶胶-凝胶途径制备的。X 射线衍射分析证实了制备的 Cr3+ 离子掺杂 Ni-Ba-Co 铁氧体的尖晶石相结构。通过谢勒公式，计算平均微晶尺寸。同时，从傅里叶变换红外光谱中，发现了590 cm-1 附近的吸收峰；可以推断制备的样品具有尖晶石结构。透射电子显微镜图像显示制备的颗粒具有球形立方体形状并且在纳米尺寸范围内。EDS 分析了样品的元素和成分。振动样品磁强计结果显示，随着Cr3+离子掺杂水平从0增加到0.075，Ms、Mr和Hc的值增加；当 x = 0.1 时，上述三个略有下降。这表明适当的掺杂含量可以增强磁性。该材料可用于音频、录像带和信息存储行业的高密度数字记录盘。