Magnetic properties of current-annealed amorphous thin films

摘要

An annealing technique based on electrical current heating is extended from the case of metallic ribbons to thin films, by taking into account the role of thermal dissipation played by the film substrate. It has been employed in order to study the evolution of the magnetic properties with increasing annealing current intensity, and thus annealing temperature, of amorphous Fe-Co-Nb-Si-P-B thin films. Results are compared with conventionally annealed samples, treated in furnace at similar temperatures. Joule heating turns out to be more effective in softening the magnetic properties of the studied alloy in thin film form, with respect to furnace annealing. Additionally, Joule heating (performed at low current intensities) is able to promote the development of a spin reorientation transition in the studied film, which results in the appearance of a transcritical hysteresis loop and a dense stripe domain configuration.