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Luzuriaga, J., A. Badía-Majós, G. Nieva, J. L. Giordano, C. Lopez, A. Serquis, and G. Serrano. "Magnetic relaxation induced by transverse flux shaking in MgB2 superconductors." Superconductor Science and Technology 22 (2009): 15021.
Abstract: We report on measurements and numerical simulations of the behavior of MgB2 superconductors when magnetic field components are applied along mutually perpendicular directions. By closely matching the geometry in simulations and measurements, full quantitative agreement is found. The critical state theory and a single phenomenological law, i.e. the field dependence of the critical current density Jc(B), are sufficient for a full quantitative description of the measurements. These were performed in thick strips of carbon nanotube doped MgB2 samples. Magnetization was measured in two orthogonal directions using a SQUID magnetometer. Magnetic relaxation effects induced by the application of an oscillatory perpendicular field were observed and simulated numerically. The measurements confirm the numerical predictions, that two relaxation regimes appear, depending on the amplitude of the applied magnetic field. The overall agreement constitutes a convincing validation of the critical state model and the numerical procedures used.
Luzuriaga, J., A. Badía-Majós, G. Nieva, J. L. Giordano, C. Lopez, A. Serquis, and G. Serrano. "Experimental and numerical study of transverse flux shaking in MgB2 superconductors." In Journal of Physics: Conference Series, 012009. Vol. 167., 2009.
Abstract: Magnetization measurements in the mixed state of thick strips of carbon nanotube
in crossed fields configurations are reported, together with numerical simulations
performed with a geometry equivalent to the sample shape. The samples were subjected to
magnetic field components along mutually perpendicular directions, an oscillatory field in one
direction and a remanent magnetization in the perpendicular direction. The magnetic response
along the oscillatory field and the magnetic relaxation perpendicular to it are observed and
simulated using the critical state theory. A remarkable quantitative agreement between the
experiment and the theory was obtained.