Thermal domain drag effect in amorphous ferromagnetic materials. II. Experiments

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Ferromagnetic domain walls are observed to move from the hot to the cold end of samples of amorphous (Co92.5Fe7.5)78Mo2B15Si5 subjected to a constant temperature gradient dT/dx. An ac magnetic field H0E parallel to the easy axis is used to decrease pinning forces on the walls. The critical temperature gradient (dT/dx)c required to move walls is of order 102 K/mm. The linear decrease of (dT/dx)c with increasing H0E indicates that pinning of the walls by the two ends of the sample is dominant over bulk pinning. The dependence of (dT/dx)c on sample length and thickness indicates that the Nernst–Ettingshausen drive mechanism is dominant over competing drive mechanisms. The speed of walls has been measured and is found to increase with increasing temperature gradient.