Initially formed amorphous GeTe layer crystallizes during growth by molecular beam epitaxy, as critical film thickness is reached. A remarkable change in bonding mechanism and improvement in atomic order are observed, in striking contrast to conventional lattice-matched epitaxial systems. Supported by density function theory calculations, resonant bonding is shown to be less favorable in an ultrathin GeTe film.
- Ruining Wang
- Wei Zhang
- Raffaella Calarco
