Development And Application Of Post-Data Processing Software For VNA-FMR Ferromagnetic Resonance Spectrometer

Ferromagnetic Resonance(FMR)test is the most commonly used method to characterize the magnetic and magnetization dynamics of materials.It is also a very important tool for studying magnetic materials and spintronic devices.It has been widely used in magnetic thin films and magnetic multilayers.Characterization of the dynamic and static magnetic properties of nanomaterials,superlattice materials,etc.The ferromagnetic resonance test can be roughly divided into two categories:microwave cavity ferromagnetic resonance and broadband ferromagnetic resonance according to the test frequency range.In addition,there are some special ferromagnetic resonance testing methods,such as time-domain ferromagnetic resonance testing.The ferromagnetic resonance test based on the cavity method has simple data analysis,but it can only realize the ferromagnetic resonance test of a single frequency point.Broadband ferromagnetic resonance test equipment based on microwave test equipment such as Vector Network Aanylzer(VNA)has the ability to test and analyze ferromagnetic resonance in a larger frequency range.However,the data post-processing process of this type of test method is complicated,and manual analysis is inefficient.In response to this situation,this article has compiled and developed a comprehensive data analysis software integrating VNA-FMR and Phase-FMR test data post-processing functions,and applied the developed software to the research on the high-frequency characteristics of NiFe-based ferromagnetic composite films.The main work and results of this thesis are as follows:1.Using a series of fitting methods such as derivative divide,use MATLAB to complete the programming of the ferromagnetic resonance data post-processing system.The characteristics of the system include: simple operation,high accuracy of fitting,and application of a variety of test methods.The system's functions include: the overall data set two-dimensional pseudo-color map display,single field point(frequency point)data background removal and fitting,in-plane and out-of-plane rotation angle line width component analysis,etc.Compared with the existing ferromagnetic resonance data post-processing system,the advantage of this system lies in the realization of one-key batch import and fitting,which improves the efficiency of data analysis under the premise of ensuring accuracy.Integrate the data post-processing process of multiple test equipment and test methods into one system to facilitate repeated observation of the analysis results of different types of test data at any time during the research process.2.The high-frequency characteristics of NiFe-based ferromagnetic composite films are studied by using the compiled system.NiFe-based ferromagnetic composite films were prepared by radio frequency magnetron sputtering,and combined with X-ray diffraction spectrometer(XRD),magnetic spectroscopy and other testing methods,the effects of YIG content and radio frequency power changes on the microstructure and height of NiFe-based composite films were studied in detail.The influence of frequency and magnetic characteristics.The experimental results show that with the increase of the YIG doping content,the coercivity and resistivity of the film increase significantly,and the spin wave resonance mode caused by the eddy current effect will gradually disappear.The introduction of YIG will increase the scattering linewidth of the film dimagnon,indicating that the influence of short-range defects in the film is enhanced.In the variable power research,the obvious double peak phenomenon appeared in the magnetic spectrum test of the sample with the power above 60 W.According to the XRD test results,it may be caused by the YIG phase formation caused by the heating of the substrate.Based on the existing universal broadband ferromagnetic resonance test equipment,this article extends its ability to automatically process and analyze data.This not only provides a certain reference for related research on magnetic materials,but also provides a new research direction for further enhancing the characterization capabilities of existing ferromagnetic resonance test equipment in the future.