Spin easy axis switching from the out-of-plane to in-plane direction driven by 2{\%} Fe doping in Sr$_{\mathrm{\mathbf{4}}}${Ru}$_{\mathrm{\mathbf{3}}}${O}$_{\mathrm{\mathbf{10}}}$

Sr$_{\mathrm{4}}$Ru$_{\mathrm{3}}$O$_{\mathrm{10}}$, a layered strongly correlated system, has been known as an itinerant ferromagnet with T$_{\mathrm{C\thinspace }}$\textasciitilde 105 K $^{\mathrm{[1]}}$; its spin easy axis lies along the c-direction. A puzzling phenomenon of its FM state is that a metamagnetic transition can be induced by in-plane field $^{\mathrm{[1,\thinspace 2]}}$. In this presentation, we will report that 2{\%} Fe-doping in this material results in drastic changes in its FM properties: its spin easy axis switches from the out-of-plane to in-plane direction, whereas the metamagnetic transition takes place for the field aligned along the out-of-plane direction. These surprising phenomena could be attributed to strong lattice-orbital coupling. The possible scenario is that Fe acts as a strong scattering center, thus resulting in global structure distortion, which in turn leads to the change of the Ru 4$d_{xy}$ and $d_{xz/yzz}$ orbital states. [1] G. Cao, L. Balicas, W. H. Song, \textit{et al.} \textit{Phys. Rev. B} \textbf{68}, 174409(2003) [2] Z. Q. Mao, M. Zhou, J. Hooper, \textit{et al. }Phys. Rev. Lett. \textbf{96, }077205 (2006)