We introduce the Cavity-FMR devices measuring the ferromagnetic resonance (FMR) signals, and phenomenological description of FMR signals measured in ferromagnetic thin films. The effective magnetization and g-factor can be obtained from the FMR field (H_res) measured at out-of-plane angle of ferromagnetic thin films and the anisotropy fields can be obtained from the H_res measurement at in-plane angle. We also present the analysis method of FMR linewidth (ΔH_PP) due to the Gilbert damping factor, inhomogeneous magnetic properties and spin wave scattering, respectively.

The ferromagnetic resonance (FMR) including inverse spin hall effect (ISHE) by spin pumping is a useful method to analyze the spin dynamics of ferromagnetic material and the spin-charge conversion of ferromagnet/normal metal heterostructure. For localization of the ISHE-FMR system, we have developed a customizable ISHE-FMR system. The developed ISHE-FMR system can simultaneously measure the ISHE voltage and FMR signal in the various range of temperature (4~300 K). From this ISHE-FMR system, we measured the FMR derivative absorption signals and ISHE voltage of molecule-based ferromagnetic insulator (Cr-PBA, Tc = 220 K) and Co thin film. And we show the design and manufacture process of ISHE-FMR system briefly, and discuss the Gilbert damping constant of all the test samples compared with reference value.

Brillouin light scattering (BLS) is used to measure thermally exited surface and bulk spinwave (SW) modes in various magnetic materials and it is to study SW frequency ranges up to sub-hundred GHz. In this review, we discuss magnetic properties on magnetic thin films including Heisenberg interaction, in-plane biaxial magnetic anisotropy, perpendicular magnetic anisotropy, Dzyaloshinskii-Moriya interaction probed by using a BLS spectroscopy.

For the development of antibody therapeutics, magnetoresistance (MR) characteristics according to the size and distribution of superparamagnetic magnetic beads (MBs) and magnetic nanoparticles (MNPs), each with surfaces functionalized by silanol and carboxyl groups with magnetite (Fe₃O₄) cores, were investigated. Particles of different sizes were placed within a 1 mm space in the center of a plastic tank that could contain up to 10 μl in volume. A magnetic field was applied to the tank in order to distribute the particles. The minimum MR value, MR ratio, and solution coercivity obtained from the voltage curve, measured according to the strength of the external magnetic field passing through the MBs solution, were 3.567MΩ, 1.1%, and 400 Oe, respectively; for the MNPs solution, 0.245MΩ, 50%, and 184 Oe, respectively. The MNPs solution containing 0.35 μm sized particles showed a much more sensitive change in MR properties than the MB solution with 1 μm sized particles. This phenomenon was analyzed to have been caused by the estimated split distance (ESD) created by the movement of different sized magnetic particles and whether a large or small number of estimated degree of solution pathway (EDSP) were created in response to an external magnetic field. It was discussed that these characteristics could potentially be used to control the function of various biomolecules, including antibodies conjugated to the surface of MNPs.

In PHR sensor, PHR signals V_PHR was proportional to the driving current, V_DC and V_2f signals were caused by self field by sine wave driving current. The V_PHR and V_2f by sine wave driving were well fitted with calculated one by single domain model. The V_PHR by square wave driving were measured as the 1f, 3f, 5f .... signals, which higher order harmonics were included in square wave. The V_DC and by sine and square wave driving showed same magnetic field dependence and The magnetic bead signals by square wave driving were 2 times higher than that by sine wave driving. Thus square wave driving can be used for the accuracy improvement of biosensors.