Influence Of Field Direction Research Articles

Influence of Field Direction and Conductor Aspect Ratio on Coupling Losses: Measurements and Modeling on the JT-60SA TF Conductor

Influence of Field Direction and Conductor Aspect Ratio on Coupling Losses: Measurements and Modeling on the JT-60SA TF Conductor

Influence of field direction on magnetization measurement for NbTi wire

Upper critical field, μ0Hc2 was important to the type-II superconductors and interested to study for the nature of transition points near the upper critical field. A standard NbTi wire was used to explore the influence of magnetic field direction on magnetization measurement. The external field was applied in the direction of perpendicular or parallel to the sample axis. It swept up to 12 Tesla with the temperature changing from 4.2 K to 9.5 K in a Vibrating Sample Magnetometer (VSM) system. Upper critical fields such as μ0H irr(T) and μ0Hc2(T) were observed on the measured curves. These upper critical fields showed a linear relation dependent on temperatures. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Magnetization Process Associated with Rearrangement of Martensite Variants in Iron-Based Ferromagnetic Shape Memory Alloys

ABSTRACTMagnetization processes of Fe-31.2Pd(at.%) and Fe3Pt (S ≈ 0.8) single crystals in martensite state have been examined in order to confirm the propriety of the condition for the rearrangement of variants under magnetic field: τmag>τreq, where τmag is the magnetic shear stress and τreq is the shear stress required for the rearrangement. When the magnetic field is applied along the [001] direction of each specimen, the magnetization curve shows a large hysteresis due to the rearrangement of variants. Its area, i.e., energy dissipation, is nearly the same as that obtained by stress-strain curves, suggesting the path of the rearrangement of variants by magnetic field is essentially the same as that by external stress. From the magnetization curve, the uniaxial magnetocrystalline anisotropy constant Ku is estimated: it is about 350 kJ/m3 for Fe-31.2Pd at 77 K, and is about 500 kJ/m3 for Fe3Pt at 4.2 K. The maximum of τmag, being evaluated from Ku and twinning shear, is about 2.8 MPa for Fe-31.2Pd at 77K and is about 4.3 MPa for Fe3Pt at 4.2K. For Fe-31.2Pd, the value of τreq is obtained by tensile tests at 80 K to be 0.5–2.5MPa, and the above condition is satisfied. The above condition is also confirmed to be adequate by examining the influence of field direction on the magnetic filed-induced strain.