The anisotropy dependence of ferromagnetic domainhyphen;wall widths in crystalline and amorphous metals

摘要

We have used the techniques of Lorentz electron microscopy to study the behavior of ferromagnetic domainhyphen;wall widths as a function of the magnetic anisotropy constantKand the foil thicknessD. This was done by varying the temperatureTin crystalline iron and in amorphous Fe75P15C10for variousDrsquo;s. Our results are compared with existing theories. We observed an increase in wall width with temperature in crystalline iron and explained this by assuming the width of the wall to be an explicit function of both the anisotropy constantK(T) and the temperatureT. After removing the explicit temperature dependence, the experimental results yielded an expression for the wall width of the form 2.5D/K1/6within the range of sim;1000 Aring; foil thickness. An increase in wall width with temperature was also observed for walls in amorphous Fe75P15C10. From the measured wall structures we obtained a value of sim;104erg/cm3for the effective anisotropy constant of this amorphous alloy.