Fig. 3: MOKE and MFM characterizations of the Co-BP device.
From: Electric field-tunable ferromagnetism in a van der Waals semiconductor up to room temperature
a Kerr signal and MR signal. Blue region indicates the in-plane switching and the orange region indicates the out-of-plane saturation during the field scan. b A comparison of Kerr signals on Co-BP and Co on Au pads. Inset: Optical micrograph showing the Co-BP region. c MFM characterization of the sample at 1.7 K and under \({V}_{{{{\rm{g}}}}}=\) − 40 V. At, as \({B}_{\perp }\) increases, a darker region (the edge is denoted by the dashed line) begins to appear in the Co-BP region. This corresponds to a negative frequency shift (Δf) that represents an attractive force between the cantilever and sample surface, indicating Co-BP becomes magnetic. d MFM profiles of the line scans for frequency shift (Δf) from c. The curves are shifted vertically for better presentation.
