Battiato, M. 2013. Superdiffusive Spin Transport and Ultrafast Magnetization Dynamics: Femtosecond spin transport as the route to ultrafast spintronics. Acta Universitatis Upsaliensis. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1061. 62 pp. Uppsala. ISBN 978-91-554-8722-5. The debate over the origin of the ultrafast demagnetization has be...

The developed subdomain model accounting for tooth-tips can accurately predict the open-circuit, armature reaction and on-load field distributions in surface-mounted permanent magnet machines. Based on this field model, their electromagnetic performance of the machine, such as the cogging torque, back-EMF and electromagnetic torque, and winding inductances are calculated. The model can also be ...

When a composite of nonlinear particles suspended in a host medium is subjected to a sinusoidal electric field, the electrical response in the composite will generally consist of alternating current (ac) fields at frequencies of higher-order harmonics. The situation becomes more interesting when the suspended particles are graded, with a spatial variation in the dielectric properties. The local...

Introduction: When a large hypervelocity impact occurs on a planetary body such as Mars, the kinetic energy of the impactor is partitioned primarily into 1) kinetic energy of the planetary crust and mantle as they deform and flow in response to the impact, 2) heating, melting and vaporization of impactor, crust and mantle material and 3) shockwaves that travel throughout the entire volume of th...

Highly uniform and well-aligned one-dimensional Ni nanochains with controllable diameters, including 33, 78, and 120 nm, have been synthesized by applying an external magnetic field without any surface modifying agent. The formation can be explained by the interactions of magnetic dipoles in the presence of applied magnetic field. Magnetic measurements demonstrate that the shape anisotropy domi...

Demagnetization in a thin film due to terahertz pulse of magnetic field is investigated. Linearized Landau-Lifshitz-Gilbert (LLG) equation the Fourier space describe magnetization dynamics derived, and spin wave time evolution studied. Finally, demagnetization recent experimental observations on similar system compared. As result, marginal role loss established.

The transport critical current Jc in a polycrystalline superconductor is a hysteretic function of applied magnetic field H0 due to flux trapping by grains. This effect has been observed by several groups and attempts have been made to calculate the intergranular field Hi as a function of the applied H0 in terms of an effective geometrical demagnetization factor D. In general a first-principles ...

The laser-induced demagnetization of a ferromagnet is caused by the temperature of the electron gas as well as the lattice temperature. For long excitation pulses, the two reservoirs are in thermal equilibrium. In contrast to a picosecond laser pulse, a femtosecond pulse causes a non-equilibrium between the electron gas and the lattice. By pump pulse length dependent optical measurements, we fi...

Understanding the magnetostatic field effects of a single-domain particle on its neighbors during thin film deposition and magnetic recording is essential to the development of magnetic recording media. Here, we present a unique study of such effects using nanofabrication technology and magnetic force microscopy ~MFM!. We fabricated pairs of single-domain cobalt bars. Each bar is 35 nm thick, 5...