6533b86dfe1ef96bd12c9f55
RESEARCH PRODUCT
Unraveling the LiNbO3 X-cut surface by atomic force microscopy and density functional theory
Angelika KühnleSebastian RodeWolf Gero SchmidtSimone SannaStefanie Klassensubject
Kelvin probe force microscopeMaterials scienceAtomic force microscopyLattice (order)Fast Fourier transformOxygen ionsTheoretical modelsDensity functional theoryAtomic physicsCondensed Matter PhysicsElementary charge530Electronic Optical and Magnetic Materialsdescription
The ${\text{LiNbO}}_{3}$(2$\overline{1}\overline{1}0$) surface, commonly referred to as X-cut, is investigated by means of atomic force microscopy and first-principles calculations. Atomically resolved atomic force microscopy images show geometrical patterns not compatible with truncated bulk terminations. Fast Fourier transformation of the real-space images shows an oblique surface unit cell with lattice parameters of $a=0.75\ifmmode\pm\else\textpm\fi{}0.02$ nm, $b=0.54\ifmmode\pm\else\textpm\fi{}0.02$ nm, and $\ensuremath{\alpha}=94.{8}^{\ensuremath{\circ}}$. Comparing these experimental results with the theoretical models of stable surface terminations provides clear evidence for the formation of a -${\text{Li}}_{12}$ termination. The LN X-cut is, thus, characterized by a nonstoichiometric and Li-enriched composition. An analysis of the surface electronic charge indicates that the atomic force microscopy contrast is governed by the charge accumulation at the oxygen ions.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2014-02-07 |