Does the flexibility of ferromagnetic domain walls affect their mobility?

Abstract

Earlier measurements of the velocity v of 180° domain walls in the ferromagnetic Ni-base alloy NIMONIC PE16 are analysed in the light of a recently published model by Gaunt (1983). The temperature range covered by the measurements is 2·2 to 5 K. v is related to the activation energy E(H) and the temperature T by an Arrhenius equation, where H is the applied magnetic field. The function E(H) can be derived from the interaction energy W(x) between the domain wall and an obstacle present in the specimen. Gaunt has stressed the effects of the finite wall flexibility on the function E(H). For a certain potential W(x), E(H) which is derived for rigid walls, as well as E&(H) which can be derived for flexible walls, are in agreement with the data for v(H, T) obtained for PE16. Thus, it is not possible to conclude from such data whether bowing of domain walls really affects their mobility. Gaunt has predicted that E&(H) should lead to a superior description of the experimental data.