Two-channel anomalous Hall effect in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>SrRuO</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:math>
Graham Kimbell, Paul M. Sass, Bart Woltjes, Eun Kyo Ko, Tae Won Noh, Weida Wu, Jason W. A. Robinson
Abstract
The Hall effect in ${\mathrm{SrRuO}}_{3}$ thin films near the thickness limit for ferromagnetism shows an extra peak in addition to the ordinary and anomalous Hall effects. This extra peak has been attributed to a topological Hall effect due to two-dimensional skyrmions in the film around the coercive field; however, the sign of the anomalous Hall effect in ${\mathrm{SrRuO}}_{3}$ can change as a function of saturation magnetization. Here we report Hall peaks in ${\mathrm{SrRuO}}_{3}$ in which volumetric magnetometry measurements and magnetic force microscopy indicate that the peaks result from the superposition of two anomalous Hall channels with opposite sign. These channels likely form due to thickness variations in ${\mathrm{SrRuO}}_{3}$, creating two spatially separated magnetic regions with different saturation magnetizations and coercive fields. The results are central to the development of strongly correlated materials for spintronics.