A Magnetization Measuring Instrument—Vibrating Sample Magnetometer

摘要

A measurement mechanism is introduced in this thesis, which is usually used in the production 、research and development of the magnetic materials and can accurately measure the magnetic characterization curve of this magnetic material, it is the most popular magnetization measuring instruments, Vibrating Sample Magnetometer （VSM ）. It uses an open-circuit technique in which the magnetization measurement is based on the measurement of flux changes when a sample moves through the detection coils. The simplest measurement of the magnetic flux change is the extraction method, in which a sample initially at the center of the detection coil in the presence of a field is quickly moved to a point far away from the coil. The change in flux, which is proportional to the magnetic moment of the sample, is calculated by integrating the electromagnetic force (emf) induced in the detection coil. It emphasis on the operating 、 principle 、characteristic 、construction and function of the high degree of accuracy of the Vibrating Sample Magnetometer, and also proceed the analysis of data sampling 、data handling and calculation, which uses computer as interface. Finally, 7404 model of Vibrating Sample Magnetometer is taken as an example, which is used to characterize the magnetic properties of (FePt/C)10 multilayer films. The magnetic hysteresis loop 、the isothermal remanence (IRM) 、 the DC demagnetization (DCD) and the moment M vs. time (M -t plot) are measured by VSM. These parameters are most often used to characterize the magnetic properties 、investigate the intergranular exchanging and the thermal stability of materials,etc.