We investigated the magnetocrystalline anisotropy of pure α''-Fe₁₆N₂ by using full-potential linearized augmented plane wave method (FLAPW). A very high magnetic moment was obtained for Fe (4d) site due to the lattice expansion in the z-direction, while the magnetic moment of Fe (4e) and (8h) site were suppressed due to hybridization with neighboring N atom. The calculated spin magnetic moments for different Fe sites (4d, 4e and 8h) were in good agreement with previously reported values. Due to the tetragonal distortion, we found a very large uniaxial anisotropy constant of 0.58 MJ/m³. Besides, a high value of magnetization of 1.76MA/m was obtained. In additon, the estimated coercive field and maximum energy product of 6.51 kOe and 71.7 MGOe were obtained for pure α''-Fe₁₆N₂. This may suggest that the α''-Fe₁₆N₂ can be utilized for potential rare-earth free permanent magnet material.

We have studied electronic and magnetic structure of cubane-type Cu magnetic molecule using density functional method. The calculated density of states show that Cu has 3d x²-y² hole orbital because of short distances between Cu atom and in-plane 4 ligand atoms. The calculated total energy with in-plane antiferromagnetic spin configuration is lower than those of ferromagnetic configurations. The calculated exchange interaction J between in-plane Cu atoms is much larger than those between out-plane Cu atoms, since the x²-y² hole orbital ordering of Cu 3d orbitals induces strong super-exchange interaction between in-plane Cu atoms.

We have investigated the electronic structures of intermetallic multilayer (ML) films of [Co(2Å)/Pd(xÅ)] (x: the thickness of the Pd sublayer; x = 1 Å, 3 Å, 5 Å, 7 Å, 9 Å) by employing soft X-ray absorption spectroscopy (XAS) and soft X-ray magnetic circular dichroism (XMCD). Both Co 2p XAS and XMCD spectra are found to be similar to one another, as well as to those of Co metal, providing evidence for the metallic bonding of Co ions in [Co/Pd] ML films. By analyzing the measured Co 2p XMCD spectra, we have determined the orbital magnetic moments and the spin magnetic moments of Co ions in [Co(2Å)/Pd(xÅ)] ML films. Based on this analysis, we have found that the orbital magnetic moments are enhanced greatly when x increases from 1 Å to 3 Å, and then do not change much for x ≥ 3 Å. This finding suggests that the interface spin-orbit coupling plays an important role in determining the perpendicular magnetic anisotropy in [Co/Pd] ML films.

The effect of thermal-nitrification on L1o transfomation in nano-sized FePt particles was studied. As-synthesized FePt nanoparticles by thermal decomposition method have fcc structured phase and their Hc and Ms were 247.34 Oe and 27.308 emu/g, respectively. According to the XRD analysis, phase transformation from fcc (face centered cubic) to fct (face centered tetragonal) structure was revealed by heating under NH₃+H₂ mixed-gas atmosphere. Also a slight shift of each (111) peak indicated phase transformation from fcc to fct structure. Hc and Ms of fct FePtN were 1058.2 Oe and 32.718 emu/g, respectively. The nano-sized FePtN magnetic particles synthesized by thermal decomposition method and mixed-gas nitrification are expected for advanced applications such as high density magnetic recording media and biomedical materials.

In this study, we have constructed a measuring system to investigate tensile stress of tendons, which is employed in bridges, by means of the magnetic non-destructive testing (NDT) method. For the twisted 7-strands tendon, we have used Wiedemann effect. An ac current was applied to the tendon and voltage induced from Search Coil on Tendon (SCT) under applying tensile stress was measured. The measuring system consists of tensile stress applying apparatus up to 2 GPa, and ac current supply to apply current to the tendon directly to magnetize the tendon. We have invested two kinds of tendon which were produced by different companies for testing with constructed measuring system. Voltage induced from SCT was decreased up to 1.5 GPa linearly and two kinds of tendon which were produced by different companies shows similar trends. Thus, Wiedemann effect was also applicable to measure tensile stress of tendon by means of magnetic NDT.

There is a growing demand for non-contact current measurements for efficient use of electrical power and energy saving. In this study, I propose a non-contact current sensor using LC resonance by a resonance circuit composed of a sensor coil and 2 coupling coils for enabling a wireless measurement. The inductance of the sensor coil, which could be changed by applied current, causes the change of resonance frequency of the resonance circuit. A pair of magnet was attached to the ferrite core to apply a bias magnetic field that enabled the determination of the current direction. We obtained an output voltage change of 18 V with the current of −3~3 A. But, the output was nonlinear. In order to realize the non-contact current measuring method proposed in the present study, there is a need for a strict investigation of linearity and resolution for the future study.

To evaluate the effect of flip angle on flow rate measurements obtained with phase contrast MRI according to the flip angle degree in ascending aorta and velocity encoding (VENC) was (150 m/s). 1.5T MRI in patients 17 (female: 8, male: 9, mean age 57.9 ± 15.4) as a target by applying a non-breath holding techniques to flip angle VENC (150 cm/s) in each of the ascending aorta was measured by changing 20°, 30° and 40°. Blood was obtained a peak velocity, average velocity, net forward volume, net forward volume/body surface area. Ascending aorta from average velocity (AV) measured the average value of the flip angle 20° (9.87 cm/s), 30° (9.6 cm/s) and 40° (10.05 cm/s). Blood flow VENC in was blood flow change in flip angle change was high most blood flow measurement when the flip angle 30° in VENC, crouching each blood flow is also proportional to the increases in the 20° to 40° and was increased, the deviation of the peak velocity and the average velocity is the smallest deviation from the flip angle 30°. Flip angle 20°, 30° and 40° in peak velocity, average velocity, net forward volume, net forward volume/body surface area was no statistically significant difference (p > .05). Blood flow velocity and blood flow is measured by applying to adjust the flip angle accurately calculate the blood flow is important information for diagnosis and treatment of cardiovascular diseases, and can help in the examination on the blood flow measurement.