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Iron Whiskers under the Effect of Time‐Dependent Fields
Author(s) -
Trueba A.
Publication year - 1971
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2220430117
Subject(s) - whiskers , whisker , condensed matter physics , hysteresis , coercivity , magnetization , field (mathematics) , magnetic field , constant (computer programming) , physics , time constant , materials science , mathematics , quantum mechanics , composite material , electrical engineering , pure mathematics , engineering , computer science , programming language
Magnetization reversal has been studied in iron whiskers under the influence of time‐dependent magnetic fields. Switching sometimes occurs by propagation of a single Bloch wall. If the applied field is H = λ t , where λ, is a constant, it is possible to investigate various magnetic magnitudes as a function of λ. If λ < 10 11 A m −1 s −1 , and because of the low value of the wall mass, the results are very simple and all the magnetic magnitudes are strongly dependent on λ. Specifically, the switching time is t s = K p λ −1/2 , where K p is a constant which depends upon the viscous damping parameter, whisker's size, and other magnitudes; the coercive “dynamic” field is given by H c = H p + ( K p /), λ 1/2 , where H p is the propagation field. These relations have been tested on several {100} oriented whiskers and values of K p have been computed by measuring H c and t s vs. λ. The results are consistent for λ < 10 7 A m −1 s −1 and agree very well with theory. It is possible to deduce the wall mobility ( C ) from K p taking into account that K p 2= 2 l/C ( l is the length of the whisker). All this enables us to understand the deformations of hysteresis loops when the frequency or other parameters of the applied field are changed.