How to cleave cubic perovskite oxides

TL;DR

This paper presents a strain-assisted cleaving method for preparing high-quality, bulk-terminated surfaces of cubic perovskite oxides, demonstrated on SrTiO3, KTaO3, and BaTiO3, facilitating better theoretical and experimental studies.

Contribution

It introduces a transferable, optimized cleaving technique for cubic perovskite single crystals, enabling reproducible, well-defined surfaces for research and applications.

Findings

Successful cleaving of SrTiO3, KTaO3, and BaTiO3 surfaces.

Large-area, well-defined surface morphology achieved.

Guidelines for distinguishing cleaved from fractured surfaces.

Abstract

Surfaces of cubic perovskite oxides attract significant attention for their physical tunability and high potential for technical applications. Bulk-terminated surfaces are desirable for theoretical modelling and experimental reproducibility, yet there is a lack of methods for preparing such well-defined surfaces. We discuss a method for strain-assisted cleaving of perovskite single crystals, using a setup easily transferable between different experimental systems. The details of the cleaving device and the procedure were optimized in a systematic study on the model SrTiO$_3$. The large-area morphology and typical distribution of surface terminations on cleaved SrTiO$_3$(001) is presented, with specific guidelines on how to distinguish well-cleaved surfaces from conchoidally fractured ones. The cleaving is applicable to other cubic perovskites, as demonstrated on KTaO$_3$(001) and BaTiO$_3$(001). This approach opens up a pathway for obtaining high-quality surfaces of this promising class of materials.