A series of cobalt-doped nickel ferrite nanoparticles, Co_x Ni_1−xFe₂O₄ (x = 0.2, 0.4, 0.6, 0.8), was synthesized by hydrothermal method at low temperature, and its structural, morphological, and magnetic properties have been examined. The structural properties were studied from X-ray diffraction with crystallite size 18.9 to 24.09 nm. The presence of Co, Ni, Fe, and oxygen as well as purity of the synthesized nanoparticles was confirmed by energy-dispersive spectrum (EDS). The study of morphology carried out with field emission scanning electron microscopy (FESEM) reveals that the prepared nanoparticles are oriented as non-porous and stone-like and observed strong agglomeration between the particles. The magnetic properties such as saturation magnetization, coercivity, and retentivity have been calculated by vibrating sample magnetometry (VSM); saturation magnetization and remanence magnetization from M-H loop suggested that these materials are applicable for the memory device applications, and low coercive field and S-shaped hysteresis revealed just about superparamagnetic nature.

一系列钴掺杂的镍铁氧体纳米颗粒，Co _x Ni _{1− x} Fe ₂ O ₄（x ＝ 0.2、0.4、0.6、0.8），是在低温下通过水热法合成的，并且已经对其结构，形态和磁性能进行了研究。通过X射线衍射研究了微晶尺寸为18.9至24.09nm的结构性质。通过能量色散谱（EDS）证实了Co，Ni，Fe和氧的存在以及合成纳米颗粒的纯度。用场发射扫描电子显微镜（FESEM）进行的形态学研究表明，所制备的纳米颗粒定向为无孔和石头状，并且观察到颗粒之间强烈的团聚。诸如饱和磁化强度，矫顽力和保持性之类的磁性已经通过振动样品磁强计（VSM）进行了计算。