Günther, C.M.; Radu, F.; Menzel, A.; Eisebitt, S.; Schlotter, W.F.; Rick, R.; Lüning, J.; Hellwig, O.: Steplike versus continuous domain propagation in Co/Pd multilayer films. Applied Physics Letters 93 (2008), p. 072505/1-3
10.1063/1.2968305
Abstract:
We investigate the microscopic reversal behavior in perpendicular-anisotropy magnetic thin films using an integrated mask-sample design that allows probing a nanoscale sample region with soft x-rays. Local hysteresis loops and spectroholography images are obtained from the transmitted signal exploiting x-ray magnetic circular dichroism. Our data provide direct evidence of microscopic spin-flip avalanches, such as responsible for Barkhausen noise. In comparison with macroscopic magnetometry measurements we find evidence for the sputter pressure dependent introduction of local defects that prevent a continuous domain wall motion but are not strong enough to introduce the appearance of microscopic return point memory.