Figure 2. MR and Hall resistivity at 400 K.

(a) The MR versus external magnetic field (H) of four-layer graphene (Gr)/BN as a function of V_G at 400 K. The MR is maximum at the charge neutrality point (CNP, ∼10 V). (b) The MR versus H of Gr/SiO₂ as a function of V_G at 400 K. The CNP is∼25 V. (c) The Hall resistivity (ρ_xy) as a function of H at various V_G, which shows a nonlinear behaviour due to contribution from various layers. The slope changes upon crossing the CNP suggesting a change in the majority carrier type. The MR contribution arising from any geometry effect is removed from the measured Hall resistivity. (d) The fitted parameters, carrier density (n) and mobility (μ), extracted from the multi-channel model. For V_G<0, positive n₁ values indicate hole transports, whereas negative n₂ suggests electron transports.