Visualization of avalanches in magnetic thin films: temporal processing

TitleVisualization of avalanches in magnetic thin films: temporal processing
Publication TypeJournal Article
Year of Publication2009
AuthorsMagni, Alessandro, Durin Gianfranco, Zapperi Stefano, and Sethna James P.
JournalJournal of Statistical Mechanics: Theory and Experiment

Magneto-optical methods allow us to observe the dynamics of domain wall motion, but this is intrinsically a very noisy process. We discuss a new method allowing us to reduce the measurement noise, taking advantage of the acquisition of a whole temporal sequence of images. The resulting avalanche distributions give interesting hints as to the magnetization dynamics, but are strongly dependent on the size of the observation windows chosen. We investigate the effects of window size by studying finite-size scaling, and use this to extract the fractal dimension critical exponent 1/σν.