Temperature-Dependent Bending Rigidity of AB-Stacked Bilayer Graphene

Abstract

The change in bending rigidity with temperature κ(T) for 2D materials is highly debated: theoretical works predict both increase and decrease. Here we present measurements of κ(T), for a 2D material: AB-stacked bilayer graphene. We obtain κ(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 κ(T)=[(1.3 ± 0.1) + (0.006 ± 0.001)T/K] eV by fitting the data. We discuss this result in the context of existing predictions and room temperature measurements.