Abstract

The present investigation shows the viscosity and thermal conductivity of Mg²⁺ substituted nickel ferrite based magnetic fluids of different chemical compositions (Ni_1-xMg_xFe₂O₄). The nanoparticles were synthesized using a simple and cost-effective co-precipitation method. The XRD result shows the formation of a cubic spinel structure. SEM analysis confirmed the size of the nanoparticles ranges between 1 µm and 500 nm. The Experimental results show that the viscosity of magnetic fluids of two different volume fractions decreases for the rise in temperature and for the increase in rotations per minute (RPM). The results on thermal conductivity of two different volume fractions of Ni_1-xMg_xFe₂O₄ based magnetic fluids exhibit enhanced thermal conductivity than the carrier fluid (transformer oil). The thermal conductivity results were compared with Maxwell’s theoretical prediction and experimental models for confirmation.

摘要

本研究显示了不同化学成分 (Ni _1-x Mg _x Fe ₂ O ₄ )的 Mg ^{2+取代镍铁氧体基磁流体的粘度和导热性。}使用简单且具有成本效益的共沉淀法合成纳米颗粒。XRD 结果表明形成了立方尖晶石结构。SEM 分析证实纳米粒子的大小在 1 µm 到 500 nm 之间。实验结果表明，两种不同体积分数的磁流体的粘度随着温度的升高和每分钟转数（RPM）的增加而降低。_{两种不同体积分数的Ni 1-x}的导热系数结果基于Mg _x Fe ₂ O ₄的磁性流体表现出比载体流体（变压器油）增强的导热性。将导热系数结果与麦克斯韦的理论预测和实验模型进行比较以进行验证。