Dependence of characteristic interlayer vibration modes on interlayer spin arrangement in stacked graphene nanofragments

Abstract The freedom of interlayer spin arrangement could emerge when assembling small-sized graphene-based nanostructures through stacking. Its possible influence on interlayer vibrations could be significant for developing Raman probes towards small complexes and device design involving intermolecular vibronic process. In this paper, using density-functional-theory calculations on bilayer and trilayer rhombic graphene fragments, we compare finite-size analogues to interlayer shear and breathing modes regarding to ferromagnetic and antiferromagnetic interlayer spin arrangements. For bilayer units, the antiferromagnetic configuration further separate two shear mode components by around 10 cm−1, inducing a further Raman peak splitting. This response is robust regarding to slightly enlarging the fragment and increasing layer number to three. Layer breathing mode is spin-arrangement robust in bilayers but show different arrangement-sensitivity in ABA-like and ABC-like trilayers. Visualization of interface electron density reveals the dependence of anisotropic interface environment to interlayer spin arrangement and unambiguously correlates the arrangement style with shearing responses. Further application of this analysis clarifies the arrangement-based phase-cooperation in trilayer shearing. Results and analysis in this work may contribute to the characterization and design of graphene-based nanostructures as well as understanding the interfacial nature beneath their intermolecular varieties in dynamic processes.