Bio: B. Reardon is an academic researcher from California Institute of Technology. The author has contributed to research in topics: Electromagnet & Eddy current. The author has an hindex of 1, co-authored 1 publications receiving 2 citations.
TL;DR: In this article, a deposited configuration of a magnetic thin film and a coupling loop was studied with a view to the future development of integrated magnetic circuitry, and a line charge model, predicting flux linkages of coupling loops to an accuracy of about one percent was established.
Abstract: A deposited configuration, consisting of a magnetic thin film and coupling loop, was studied with a view to the future development of integrated magnetic circuitry. A line charge model, predicting flux linkages of coupling loops to an accuracy of about one percent was established. The almost complete linkage of the film flux with a deposited loop, due to the very close coupling, was verified. A decrease of about 20 percent in film flux at both ends of the easy axis was noted for the experimental assemblies used. Circulating loop currents were shown to be the chief parasitic factor which modified the switching of the magnetic film. The change in switching time due to eddy currents was small when the loop conductor size was of the same order as the magnetic film. For resistive loop loading, the average field during switching is a good measure of the slowing due to the loading. The film-loop assembly has good potentialities as a circuit element, with good transmission of both read-out and control signals occurring in the loop. The field calibration for these control signals was shown to be the same for both bias and drive field applications.
TL;DR: In this paper, the authors investigated the effects of magnetization reversal on thin permalloy films using pulse techniques and vector locus configurations and found that wall motion is predominant when no transverse bias field is applied.
Abstract: Dynamic and nearly static magnetization reversal mechanisms in thin permalloy films are investigated experimentally using pulse techniques and vector locus configurations. At least for the driving field strength used, easy-axis switching waveforms indicate that wall motion is predominant when no transverse field is applied. At a given transverse bias field, the simultaneous pick-up signals from aligned and crossed loops show that the voltage-time integral at zero crossing time of the transverse signal becomes dominant for increasing drive field. The complicated irreversible magnetization phenomena on the astroid are illustrated experimentally on the coordinate system by the vector locus for a 10 kc/s sinusoidal driving field and pulse field having 0.5 ns rise-time. Wall motion and rotation during flux reversal are clearly distinguished on these configurations for various combinations of externally applied fields. The critical angle for coherent rotation is in good agreement with that derived from the Stoner-Wohlfarth model at a 10 kc/s sinusoidal field. However, for excess driving pulse fields, the dynamic vector locus suggests that until the walls nucleate and start to move, the coherent rotation continues over the critical angle suggested by the astroid. This gives a clear answer as to the cause of the nonlinearity on the plots of the inverse reversal time vs. driving field with the transverse bias field as a parameter.
TL;DR: In this article, the fraction of magnetic thin-film flux which links a rectangular coupling loop is calculated for rectangular, square and circular film configurations based on a magnetic line charge model for the film external flux distribution.
Abstract: The fraction of magnetic thin-film flux which links a rectangular coupling loop is calculated for rectangular, square and circular film configurations. The calculation is based on a magnetic line charge model for the film external flux distribution. The results are presented in a graphical dimensionless form.