Visualization of nanodomain structures in lithium niobate and lithium tantalate crystals by scanning electron microscopy

ABSTRACT

Imaging of ferroelectric domains using scanning electron microscopy is challenging as ferroelectrics are usually highly insulating. However, micro and nanodomain patterns can be directly visualized in secondary electrons using proper parameters. Low accelerating voltage or local charge compensation allows visualizing isolated domains with sizes above 100 nm without any sample preparation. Nanodomain patterns can be visualized with resolution about 3 nm after proper preparation of the sample surface: controlled chemical etching to obtain nanoscale surface relief and subsequent covering of the crystal surface by conductive film. Features of visualization of various nanodomain structures by scanning electron microscopy are considered.

KEYWORDS:

• Ferroelectric structure
• scanning electron microscopy
• chemical etching
• nanodomains

Acknowledgments

The research was made possible in part by RFBR (14-02-31255-mol_a, 15-32-21102-mol_a_ved) and RF President grant for young scientists MK-8441.2016.2. The equipment of the Ural Center for Shared Use “Modern nanotechnology” UrFU was used. The work was supported by Government of the Russian Federation (act 211, Agreement 02.A03.21.0006). Vladimir Shur acknowledges financial support within the State Task from the Ministry of Education and Science of Russian Federation (project No. 1366.2014/236).