Optimization Of High Frequency Magnetic Properties Of Stripe-domain Thin Films By Exchange Coupling

High frequency magnetic material is the core part of the high frequency magnetic devices,and the performance of the devices is highly depended on the properties of the magnetic materials.The high frequency magnetic properties of magnetic thin film are related to the saturation magnetization,the magnetic anisotropy and the exchange coupling.In this thesis,we mainly study the high frequency magnetic properties of CoZr soft magnetic thin film with stripe domain structure by changing the exchange coupling.By changing the thickness,measuring temperature and doping concentration of non-magnetic element Zr,the exchange coupling have been changed.The main innovative results are shown as follows:1.By studying the thickness-dependent stripe-domain magnetic thin films,it is found that the width of stripe-domain can be broadened and the exchange coupling in adjacent domain can be weakened with increasing the thickness of the thin films,and the optimization of high frequency magnetic properties in the thin films can be realized.Specific results as follows: the resonance frequency of thin films in the high frequency region decreases from 5.11 GHz to 3.52 GHz and the exchange coupling field decreases from 272 Oe to 60 Oe as the thickness of thin films increases from 150 nm to 300 nm.2.By changing the temperature of stripe-domain magnetic thin film,it is found that the exchange coupling in thin films can be weakened with increasing the temperature,and the optimization of high frequency magnetic properties in the thin films can be realized.Specific results as follows: the resonance frequency of thin film in the high frequency region decreases from 4.49 GHz to 4.33 GHz and the exchange coupling field decreases from 175 Oe to 152 Oe as the measuring temperature of thin films rises from room temperature to 200 ?.3.By changing the concentration of doped non-magnetic element Zr in stripe-domain magnetic thin films,It is found that the increase of concentration of doped non-magnetic element Zr can also affect the exchange coupling interaction inthin films,and the optimization of high frequency magnetic properties in the thin films can be realized.Specific results as follows: the resonance frequency of thin film in the high frequency region increases from 4.44 GHz to 5.29 GHz and then decrease to 2.68 GHz,and the exchange coupling field increases from 170 Oe to 250 Oe and then decreases to about 80 Oe,as the concentration of doped non-magnetic elements Zr increases from 14.2% to 27.4%.In summary,we found that it is very convenient and efficient to optimize the high frequency magnetic properties in stripe-domain magnetic thin films by controlling the exchange coupling.This study provides a new method for improving the high frequency magnetic properties of many magnetic devices.