Electronic and crystal structures of nanolaminate yttrium aluminum carbide YAl3C3

Yttrium aluminum carbide (YAl3C3) was investigated by density functional theory (DFT) calculations and Cu Kα1 X-ray powder diffraction analysis to clarify the electronic and structural features responsible for its thermoelectric properties. The experimental electron density distribution from the X-ray data was consistent with the valence electron density distribution from DFT calculations. A narrow band gap was obtained in calculated density of states, which suggested a poor metallic or semi-metallic behavior. Electron density of the lowest unoccupied molecular orbitals indicated that the YAl3C3 has a nanolaminate structure along the c axis, which comprises two-dimensional electrically conductive Y and more insulating Al–C layers.