Abstract
The principal methods measuring magnetic properties of magnetic materials are Vibrating Sample Magnetometer (VSM) and Magneto Optical Kerr Effect (MOKE). The magnetization curve of a micron- or nano-sized magnetic single particle can not be measured by using VSM or MOKE unless a large array of the same particles is prepared to make signals strong enough to be measured. However, signals of individual particles in the array are averaged so some important information is hidden. In this thesis we use the micro-displacement and natural resonance frequency of a micro-cantilever to measure the magnetic properties of a micron-sized magnetic single particle. We experimentally test 5um-20um single-layer magnetic film to prove the new method we propose. We will further measure magnetic properties of submicron- or nano-sized single-layer and multilayer magnetic films in the future. First we used electron beam lithography and wet etching technique to fabricate micron-cantilever, on which NiFe magnetic thin film is deposited. The electrostatic force caused by the alternating voltage on the micro-electrodes is used to vibrate the micro-cantilever and the NiFe film thereon. The vibration of the NiFe film gives rise to the magnetic flux change in the nearby coil and an electromotive force is therefore induced in this coil. We can determine magnetic properties of magnetic thin films by measuring the induced electromotive force. In our study we obtained the double natural resonance frequency of the micro-cantilever using the oscilloscope successfully. It shows that we can detect the change of magnetic flux of the magnetic thin film by using micron-coil and then obtain the hysteresis curve of micro-magnetic film. The remaining work will be finished in the future.