Brillouin Scattering of Intercalation Tunable Acoustic Phonons in 2D Layered Materials

Brillouin light scattering is used to measure bulk and quantized acoustic phonons in a wide variety of intercalated 2D materials at hypersonic (GHz) frequencies. Using chemical, zero-valent intercalation for an entire series of elements (Ag, Au, Bi, Co, Cr, Cu, Fe, Ge, Hg, In, Mn, Mo, Ni, Os, Pd, Pt, Rh, Ru, Sb, Sn, and W), we demonstrate chemical tunability of acoustic phonon properties of 2D layered materials including h-BN, MoO3, Bi2Se3, V2O5, SnS2, Si2Te3, GaS, and GeS. Measurements yield acoustic phonon frequencies, longitudinal and transverse sound velocities, refractive indices, elastic stiffnesses, and mechanical properties.