Twisting phonons in complex crystals with quasi-one-dimensional substructures

摘要: A variety of crystals contain quasi-one-dimensional substructures, which yield distinctive electronic, spintronic, optical and thermoelectric properties. There is a lack understanding the lattice dynamics that influences properties such complex crystals. Here we employ inelastic neutron scatting measurements density functional theory calculations to show numerous low-energy vibrational modes exist in higher manganese silicides, an example These modes, including unusually low-frequency twisting motions Si ladders inside Mn chimneys, provide large phase space for scattering acoustic phonons. hybrid phonon diffuson model proposed explain low anisotropic thermal conductivity silicides evaluate nanostructuring as approach further suppress enhance energy conversion efficiency. This discovery offers new insights into structure-property relationships broad class materials with substructures various applications.