Direct imaging of octahedral tilts in LaCoO3/SrTiO3 perovskite structure by ABF image

장재혁1,2,*

1한국기초과학지원연구원 전자현미경연구부

2Oak Ridge National Laboratoy, STEM group

The corner sharing network of transition metal - oxygen octahedra (BO6) in the ABO3 perovskite of octahedral tilt patterns which affect materials properties.1 Recently, tilt discontinuities at interfaces became a topic of intense interest as a distinct instrument for engineering interface and thin film behavior, giving rise to new magnetic and electronic properties not achievable in the bulk. However, identifying the effect of octahedral tilts in the perovskite oxide materials or interfaces is difficult, because there are few ways to detect oxygens in the oxide, and it is extremely localized at the interface. Quantitative aberration-corrected scanning transmission electron microscopy (STEM) is used for identifying oxygen position, as a powerful tool that enables unit-cell-by-unit-cell analysis of octahedral tilt patterns.

In this talk, Epitaxially grown LaCoO3 and SrTiO3 films are studied with  variable thicknesses and superlattice. I will show how the octahedral tilts at the interface are changed by a thickness and a superlattice by ABF image.

[1] J. M. Rondinelli, et al MRS Bulletin 37 261 (2012).

Keywords: Octahedral tilt, ABF image, LaCoO3 Perovskite