Muneyuki Date

Diamagnetic orientation of blood cells in high magnetic field

Abstract Diamagnetic orientation of blood cells has been investigated in static high magnetic fields. The anisotropic diamagnetic susceptibility Δχ of erythrocytes and blood platelets are determined. Δχ of blood platelets is 1.5 times larger than that of erythrocytes. The contribution of microtubules to the Δχ of platelets is also discussed.

High magnetic field facility at Osaka University

Abstract The high magnetic field facility of Osaka University, equipped with several kinds of non-destructive magnets, is described. The field strength produced for practical use is up to 80 T and time durations are from 0.4 ms to 40 ms. Various kinds of experiments, from physics to biology, are carried on there.

High-Field Magnetization in PrCo2Si2 Single Crystats

Magnetic properties of PrCo 2 Si 2 single crystals have been studied by measurements of high-field magnetization, magnetic susceptibility and electrical resistivity. Anomalous behaviors in the resistivity appear at three successive magnetic phase transition temperatures of 9, 17 and 30K. The magnetic susceptibility is highly anisotropic and is analyzed using the single-ion Hamiltonian, including the crystal-field and molecular-field effects. The thermal variations of the susceptibilities can be well reproduced by the crystal-field parameters estimated from the point-charge model. Metamagnetic transitions with four steps are observable in the c -axis magnetization process up to 300 kOe. The magnetization process is discussed in terms of the incommensurate exchange field model in the Ising system proposed by Date.

Diamagnetic Orientation of Polymerized Molecules under High Magnetic Field

Diamagnetic alignment of polymerized organic molecules is discussed both from the theoretical and experimental points of view. When a number of molecules aggregate with their diamagnetic principal axes along the same direction, the resultant diamagnetic anisotropy energy becomes comparable to the thermal energy and the aggregated molecule can align under a conventional magnetic field, even at room temperatures. Polymerization of fibrin molecules is observed under magnetic fields up to 8 Tesla and considerable alignment is found. Partial alignment is seen even at 1 Tesla which means that blood clotting is influenced by use of the conventional superconducting magnet.

Magnetization of Co(SxSe1-x)2 under High Magnetic Field Up to 500 kOe

Proceeding the previous paper (J. Phys. Soc. Jpn. 46 (1979) 1474) the high field magnetization process of Co(S x Se 1- x ) 2 system for 0.70 ≤ x ≤1.00 has been investigated by means of pulse fields up to 500 kOe at fixed temperatures. The metamagnetic behaviors were observed and the phase diagram between the transition field and temperature was given. The saturation moment seemed to disappear at x ≃0.6.

Field-Induced Destruction of Heavy Fermion State in URu2Si2

High-field magnetization and magnetoresistance of URu 2 Si 2 single crystal are investigated up to 600 kOe. Three-step metamagnetic transitions are obtained with the transition fields of 358, 365 and 396 kOe at 1.3 K. The experimental results are explained quantitatively by introducing the model that the heavy Fermion state produced by the mixing of the f- and conduction electrons is destroyed by applying the field and that the exchange interactions between the recovered local f-electron magnetic moments on the uranium atom play an important role on the magnetic properties at high field. The frustration due to the exchange interactions induces the three-step metamagnetic transitions.

Field-induced metallic state in YbB12 under high magnetic field

High field magnetization and magnetoresistance of YbB 12 are investigated up to 550 kOe at low temperatures with special interest in the semiconductive band gap energy under the field. Very large negative magnetoresistance is found and the system is perfectly metallic around 500 kOe with anomalous increase in the magnetization. The experimental results are explained by introducing the model that the band gap produced by the mixing of the f- and conduction electrons is destroyed by applying the field and the released f-electron gives an anomalous magnetization. The g J -value is estimated as 1.9 for the f-level and this means that \(\varGamma_{8}\) may be most favourable for the responsible f-electron at the Fermi energy.

Eigenstates and Phase Transitions of Ising Spin Network Immersed in the Incommensurate Exchange Field

A simple incommensurate mean field model is introduced to explain complex magnetic phase diagrams of various rare-earth intermetallic compounds such as CeSb and CeBi. The eigenstates and their ener...

High Field Magnetization of Solid Oxygen

High field magnetization of solid oxygen is measured in the pulsed field up to 500 kOe. The spin flop field H c in the antiferromagnetic α-phase is investigated in detail and exchange and anisotropy fields are evaluated. The obtained data are compared with previously determined parameters and magnetic properties of three solid phases are satisfactorily explained. The α-phase is two-dimensional antiferromagnet with intrinsic Neel temperature of 30 K and the β-phase consists of the triangular spin short range order while the one-dimensional short range order exists in the A-15 type γ-phase. The corresponding exchange constants in these phases are determined by using the theory of low-dimensional magnetism and a systematic change is obtained throughout three phases.

Effects of static magnetic fields of erythrocyte rheology

Abstract The orientation of normal erythrocytes in a uniform static magnetic field (8 T maximum) has been investigated microscopically and photometrically. 1. (1) The intact erythrocytes were oriented with their disk planes parallel to the magnetic field because of the diamagnetism of the cell membrane components, particularly the transmembrane proteins (e.g., Band III, glycopholin) and the lipid bilayer. 2. (2) In contrast, the glutaraldehyde-fixed erythrocytes were oriented perpendicular to the field, perhaps because of the paramagnetism of the membrane-bound methemoglobin. 3. (3) The orientation was established within 5 s in a dilute suspension (5 × 103cells μl−1) as estimated from the change in light scattering after exposure to the magnetic field.