▎ 摘　　要

The change in bending rigidity with temperature kappa(T) for 2D materials is highly debated: theoretical works predict both increase and decrease. Here we present measurements of kappa (T), for a 2D material: AB-stacked bilayer graphene. We obtain kappa(T) from phonon dispersion curves measured with helium atom scattering in the temperature range 320-400 K. We find that the bending rigidity increases with temperature. Assuming a linear dependence over the measured temperature region we obtain kappa(T) = [(1.3 +/- 10.1) + (0.006 +/- 10.001)T/K] eV by fitting the data. We discuss this result in the context of existing predictions and room temperature measurements.