Fig. 2.
Thickness dependence of the Curie temperature (TC). Excepting the device with a thickness of 329 nm, the TCs of the devices were determined by the temperature point when the remanence becomes zero. The error bar is determined by the noise level around the point when the remanence becomes zero (Supplementary Fig. 8). The TC of the device with a thickness of 329 nm was determined from its ρxx(T) curve. Inset shows the thickness dependence of the TCs in nanoflakes with thicknesses from 5.8 to 25 nm with fitting curve. Blue dots are the TCs for the two ultra-clean devices that were covered by h-BN and PMMA in a glove box (O2 <0.1 p.p.m. and H2O <0.1 p.p.m.)