▎ 摘　　要

We report the observation of layer-breathing mode (LBM) vibrations in few layer graphene (FLG) samples of thickness from two to six layers, exhibiting both Bernal (AB) and rhombohedral (ABC) stacking order. The LBM vibrations are identified using a Raman combination band lying around 1720 cm(-1). From double resonance theory, we assign the feature as the LO+ZO' combination mode of the out LBM (ZO') and the in plane longitudinal optical mode (LO). The LOZO' Raman band is found to exhibit multiple peaks with a unique line shape for each layer thickness and stacking order. These complex line shapes of the LOZO'-mode arise both the material dependent selection of different phonons in the double resonance Raman process and from the detailed structure of the different branches of LBM in FLG.