Refined structure model of rare earth silicide nanowires on Si(001)

The internal atomic structure of terbium silicide nanowires on Si(001) is determined by scanning tunneling microscopy and high-resolution transmission electron microscopy. It is found that room temperature capping by amorphous silicon does not affect the original nanowire structure. Atomically resolved transmission electron microscopy data supported by image simulations demonstrate that the nanowires consist of two silicide layers high hexagonal TbSi2 with the c-axis aligned in the nanowire direction, in contrast to previous assumptions. An analogous atomic structure is predicted for related nanowires of other trivalent rare earth elements because of their chemical similarity.