INFLUENCE OF STRESS AND DC CURRENT ON UNIDIRECTIONAL EFFECT IN DOMAIN WALL PROPAGATION

Jozef Onufer – Ján Ziman – Mária Kladivová

   It has been found out recently that domain wall mobility in glass-coated amorphous Fe_77,5Si_7.5B₁₅ wire can be significantly different for cases when magnetization reversal caused by domain wall motion results in different orientation of magnetization, ie process of magnetization reversal runs easier when the sample is magnetized to one orientation of magnetization compared with the opposite one. This very interesting behaviour, so-called unidirectional effect is subject of the presented experimental study. Domain wall mobility can be influenced by applied tensile stress and by circular magnetic field created by DC electric current flowing through the microwire. The experimental results obtained on samples with significant unidirectional effect show that both dependences, with higher and lower wall mobility, are influenced by applied stress and circular magnetic field. However, this influence is considerably stronger for dependence with higher mobility. Qualitative interpretation of this behaviour can be based on different damping mechanisms (spin relaxation or eddy currents) of domain wall motion. Dominance of spin relaxation damping can be responsible for stronger influence of stress as well as circular magnetic field, which is observed for dependences with higher mobility.

Keywords: microwire, amorphous ferromagnetic wire, dynamics of domain wall, magnetic anisotropy

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