R-H Measurement System Based on Anomalous Hall Effect Devices

With the application of magnetic thin films becoming more and more widespread, people pay more and more attention to the performance characterization. In order to obtain a magnetic film with a specific performance, it is very important to judge the quality of the magnetic film and measure the magnetic properties of the film. However, with the increase of the film preparation process, the thickness of the prepared film is getting thinner and the magnetic moment signal contained therein is also decreased. This brings a certain degree of difficulty to the traditional measurement methods. For example, the VSM system that obtains the hysteresis loop by measuring the magnetic moment signal has become somewhat inadequate for the measurement of ultra-thin films. In order to solve this issue, a new method based on anomalous Hall effect is introduced in this paper. The test system of this system adopts the four-probe measuring method, a constant current is applied across the surface of the film sample, and the abnormal Hall voltage is measured at the other two ends. The R-H curve of the sample can be obtained through calculation. As compared to VSM measurement, this method is simpler and stable, more accurate, which can greatly reduce the anomalous Hall-effect device R-H characteristic measurement cost.