Unraveling the LiNbO3 X-cut surface by atomic force microscopy and density functional theory

Article

关键词: LITHIUM-NIOBATE;    ENERGY;   

DOI  :  10.1103/PhysRevB.89.075403

来源: SCIE

【 摘 要 】

The LiNbO3(2 (11) over bar0) 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 +/- 0.02 nm, b = 0.54 +/- 0.02 nm, and alpha = 94.8 degrees. Comparing these experimental results with the theoretical models of stable surface terminations provides clear evidence for the formation of a -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.

【 授权许可】

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