The differential sweep method as the most accurate method for measuring of magnetization

Abstract

The paper compares the magnetization curves of magnetic fluid samples measured using three different methods: the ballistic method, differential sweep, and the vibrating sample method with the use of a vibrating magnetometer. The vibrating sample method was found to yield significantly lower magnetization values than the other two methods. This lowered result is explained by the formation under the action of the field of particle aggregates that have a smaller oscillation amplitude compared to the container. The ballistic method yields magnetization values that are several percent lower than those produced by the differential sweep method. This lowered result is explained by the fact that aggregates do not have time to form during the limited measurement time when the field is turned on. Additionally, the three methods were applied to measure the magnetization curves of a magnetic fluid sample based on cured epoxy resin. In this case, the discrepancy between the results was significantly smaller. However, complete agreement was not observed. In the case of a solid sample, the exact coincidence of the magnetization curves obtained by different measurement methods is hampered by the presence of coarse particles in the sample, the magnetization relaxation time of which exceeds the measurement time.