古埃磁天平法研究ε-Fe3N磁性液体的磁化率和饱和磁化强度

摘要

Magnetic susceptibility and saturation magnetization of ε-Fe3N-based ferrofluid are studied by Gouy magnetic balance in this paper,which is added to physics experiment teaching as the comprehensive and designing experimental project.Physical connotation of magnetic susceptibility and saturation magnetization can be a thorough grasp for students by perception of the magnetic weight in a gradient magnetic field,and the students' ability of self-learning is developed in physics teaching.ε-Fe3 N-based ferrofluid is magnetized at a steady magnetic susceptibility within the range of 83 kA/m to 332 kA/m.when magnetic field intensity is more than 332 kA/m,ε-Fe3 N-based ferrofluid has a tendency to saturation and saturation magnetization is a constant.Magnetic susceptibility and saturation magnetization of three kinds of ε-Fe3N-based decrease with the increase of carrier liquid's mass.In comparison with vibrating sample magnetometer,saturation magnetization of ε-Fe3 N-based tested by Gouy magnetic balance is on the low side and relative error is less than 2 ％.Gouy magnetic balance method has a relatively high measurement precision and is suitable to test magnetic susceptibility and saturation magnetization of magnetic materials.%本文将古埃磁天平法测量ε-Fe3N磁性液体的磁化率和饱和磁化强度增设为物理实验中的设计性、研究性实验项目,通过实验过程中直接感知梯度磁场中ε-Fe3N磁性液体磁增重的变化,学生能深刻理解磁化率和饱和磁化强度的物理内涵,引领学生进行自主学习.低磁场强度83＜H0 ＜332kA/m范围内,磁性液体以恒定的磁化率磁化;近饱和磁场强度H0＞332kA/m范围内,磁性液体磁化达到饱和,饱和磁化强度Ms为常数.随载液质量增加,3种磁性液体的磁化率和饱和磁化强度逐渐减小.与振动样品磁强计相比,古埃磁天平测试的饱和磁化强度稍偏低,相对误差小于2％,说明古埃磁天平法测量精度较高,适用于测试磁性材料的磁化率和饱和磁化强度.