with base pressure $\sim$ 1 $\times$ $10^{-9}$ mbar \[24\]. The prepared CFMS thin films were *in-situ* annealed at $600^{\circ}$C/1hr to improve its crystallinity and surface quality. Reflection high energy electron diffraction (RHEED) patterns were acquired to characterize the surface and crystalline quality of CFMS layers. After the preparation of CFMS layer, Pt layer was deposited at room temperature by dc magnetron sputtering. The thickness of the films were evaluated using x-ray reflectivity (XRR) (data not shown). Ferromagnetic resonance (FMR) measurements have been performed in the frequency range 5-17 GHz on a coplanar wave guide in the flip-chip manner \[25,26\]. ISHE measurements have been performed by connecting a nanovoltmeter over two ends of the sample (sample size: 3 mm $\times$ 2 mm). The detail of the ISHE set-up can be found elsewhere \[27\].

Results and Discussion
======================

Crystalline quality {#crystalline-quality .unnumbered}
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Fig. \[fig1\] (b) and (c) show the RHEED patterns for the samples S4 and S5, respectively, observed in the MgO\[100\] and MgO\[110\] azimuths. From the streaks and spots of the RHEED patterns it is confirmed that the CFMS layer with the (001) crystalline orientation was epitaxially grown on the MgO (001) substrate. The streak lines which are elongated spots 