The isotropic magnetoresistive (MR) properties of samples fabricated with the dual- and the double-type composite structure of PtMn spin valve (SV) multilayer thin films were measured at room temperature and liquid nitrogen temperature. The MR curves of the dual-type GMR-SV multilayer of Glass/Ta(10 nm)/CoFe(6 nm)/Cu(2.5 nm)/CoFe(3 nm)/PtMn(6 nm)/CoFe(3 nm)/Cu(2.5 nm)/CoFe(6 nm)/Ta(10 nm) with a single PtMn layer in the middle are shown as a butterfly wing shape due to the antiferromagnetic PtMn layer effect. The two hysteresis square loops having an isotropic magnetic property are clearly distinguished as the coercive force (H_c) and the MR (%) obtained from MR curve which are 380 Oe, 25 Oe, and 4.3 %, 3.3%, respectively. The MR curves of the double-type GMR-SV multilayer of Glass/Ta(10 nm)/CoFe(6 nm)/Cu(2.5 nm)/CoFe(3 nm)/PtMn(6 nm)/Ta(10 nm)/CoFe(6 nm)/Cu(2.5 nm)/CoFe (3 nm)/PtMn(6 nm)Ta(10 nm) with two PtMn layers show that the H_c and MR (%) obtained from the overlapped hysteresis square of MH loop and MR curve were 375 Oe and 6.4%, respectively. These results are explained by an effect of the spin arrangement of the magnetization of each ferromagnetic layer in the dual-type GMR-SV film of one PtMn layer and double-type of two PtMn layers. H_c and MR (%) of two types of composite structures measured at 77 K were 1.2~1.5 times higher than those at room temperature due to the increase of spin dependent scattering effect of the electrons in ferromagnetic metal.

Crystallographic and magnetic effects of Ca²⁺ substitution in Sr hexaferrite were investigated in this study. Sr_1−xCa_xFe₁₂O₁₉ (x = 0, 0.5) powders were prepared by citrate auto-combustion method and subsequently sintered at 1200 ℃ under the atmosphere for 12 h. Crystallographic and composition analysis were done by using SEM, EDS, and XRD. Microscopic and macroscopic magnetism were examined by Mössbauer spectroscopy and VSM, respectively. The particle sizes distributed widely up to several μm and the samples were confirmed to be single phase M-type hexaferrite. Both the saturation magnetization (M_S) and the coercivity (H_C) decreased 14 % and 22 %, respectively as half of Sr²⁺ ions were replaced by Ca²⁺. Meanwhile, the decrease of coercivity with the substitution of Ca²⁺ could be explained by the decrease of effective magnetic anisotropy constant (K_eff). These aspects were related with the distortions of 2b and 4f₂ crystallographic sites, which were also confirmed by XRD and Mössbauer spectroscopic characterizations.

Nuclear magnetic resonance of ³¹P nuclei in CsH₂PO₄ single crystal has been investigated using by FT-NMR spectrometer in the temperature range 260 K~420 K. From the analysis of NMR spectra of ³¹P nuclei in CsH₂PO₄ single crystal, line width, relaxation time, correlation time were obtained. Chemical shift of ³¹P nucleus NMR spectra obtained decreases with increasing temperature. The line width (full width half maximum: FWHM) of ³¹P nucleus increases below 320 K and decreases above 320 K. The spin-lattice relaxation time T₁ of ³¹P nuclei linearly decreases below 340 K and linearly increases above 340 K as temperature increases. The mechanism of T₁ for ³¹P may originate from the orientation of PO₄ tetrahedron as well as dipole-dipole interaction between H-P heteronuclear interactions. The activation energies of ³¹P nucleus obtained in CsH₂PO₄ crystal below and above 340 K are E_a = 8.12 J/mol and E_a = 16.79 J/mol, respectively.

We calculated the magnetic anisotropy energy of 2-dimensional NiO cluster using OpenMX method based on density functional method with spin-orbit interaction. The calculation results show that the magnetic hard-axis is along the line between Ni and Ni atoms and the easy-axis is perpendicular to the hard-axis within plane. From the total energy fitting, the magnetic anisotropy energy is 34 cm⁻¹ and increased with decreasing Ni-O-Ni angle.

The purpose of this study was to aid in the diagnosis of knee synovial hypertrophy using DIR sequences without contrast agents. In the 3.0T MR system, the TI value was set to TI1/TI2 (2805/229 msec) and applied to the DIR technique. At this time, no contrast agent was used. In synovium and effusion, DIR showed higher SNR and CNR than T2WI and PDWI. In conclusion, the DIR technique using the proposed TI value is useful for the diagnosis of knee synovial hypertrophy as compared with the conventional image. In the future, this study will provide basic data in the study applying DIR technique to various diseases.

Development trends of electric motors including automotive applications are focusing at high-precision, high-efficiency, high-performance, small size, and light weight. In all electric machines, temperature rise has a main role in limitation of size and performance. The temperature rise changes the material characteristics used in the electric machines to deteriorate the performance and affect machine size. High performance, high-efficiency, and size reduction of the electric machines can be achieved by reduction of heat source. High-grade permanent magnet, rare-earth permanent magnet, and low-loss electric steel is able to reduce the heat source. This paper shows the influence of magnetic materials on the electric motors and the characteristics of the magnetic material required in electric motors.