File Name : figure s1.tif

Caption : fig. s1. (a) variation of d peak of raman spectra with cofeb thickness. scattered symbols are the experimental data points and solid lines are lorentzian fits. (b) variation of d peak intensity (id) and g peak intensity (ig) with cofeb thickness. inset shows perfect lorentzian shaped 2d peak for raman spectra of slg. (c) variation of id/ig ratio with cofeb thickness. (d) variation of average crystallite size (la) with cofeb thickness. 

File Name : figure s2.tif

Caption : fig. s2. (a) afm images for sub/slg/cofeb(d)/sio2(2 nm) samples. (b) comparison between average roughness vs. cofeb thickness obtained from afm and xrr measurements. (c) variation of electron density of slg, cofeb and sio2 with cofeb thickness measured using xrr measurement.

File Name : figure s3.tif

Caption : fig. s3. (a) transient reflectivity for sub/slg/cofeb(3 nm)/sio2(2 nm) at pump fluence of 5 mj/cm2 normalized w.r.t. the corresponding negative delay value. (b) transient kerr rotation for sub/slg/cofeb (3 nm)/sio2(2 nm) normalized w.r.t. the corresponding negative delay value. (c) relative variation of the peak values of transient kerr rotation and reflectivity for varying cofeb thickness.

File Name : figure s4.tif

Caption : fig. s4. (a) bias magnetic field dependent time-resolved kerr rotation data for sub/slg/cofeb (3 nm)/sio2 (2 nm) showing precessional oscillations. symbols are experimental data points and solid red lines are fit using eq 4 of the article. (b) variation of f with h for sub/slg/cofeb(d)/sio2(2 nm) samples. symbols are experimental data points and solid red lines are fits using eq 5 of the article. (c) variation of meff with 1/d. symbols are experimental data points and solid red lines are fits using eq s2. (d) variation of α with h. symbols are experimental data points and solid red lines are fits using eq s3.