Surface properties of atomically flat poly-crystalline SrTiO3.
Comparison between single- and the poly-crystalline structures provides essential information on the role of long-range translational symmetry and grain boundaries. In particular, by comparing single- and poly-crystalline transition metal oxides (TMOs), one can study intriguing physical phenomena such as electronic and ionic conduction at the grain boundaries, phonon propagation, and various domain properties. In order to make an accurate comparison, however, both single- and poly-crystalline samples should have the same quality, e.g., stoichiometry, crystallinity, thickness, etc. Here, by studying the surface properties of atomically flat poly-crystalline SrTiO3 (STO), we propose an approach to simultaneously fabricate both single- and poly-crystalline epitaxial TMO thin films on STO substrates. In order to grow TMOs epitaxially with atomic precision, an atomically flat, single-terminated surface of the substrate is a prerequisite. We first examined (100), (110), and (111) oriented single-crystalline STO surfaces, which required different annealing conditions to achieve atomically flat surfaces, depending on the surface energy. A poly-crystalline STO surface was then prepared at the optimum condition for which all the domains with different crystallographic orientations could be successfully flattened. Based on our atomically flat poly-crystalline STO substrates, we envision expansion of the studies regarding the TMO domains and grain boundaries.
Department of Physics, Sungkyunkwan University, Suwon. 440-746, Korea.
Sungmin
S
Woo
Department of Physics, Sungkyunkwan University, Suwon. 440-746, Korea.
Hoidong
H
Jeong
1] Department of Physics, Sungkyunkwan University, Suwon. 440-746, Korea [2] Insitute of Basic Science, Sungkyunkwan University, Suwon. 440-746, Korea.
Sang A
SA
Lee
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon. 440-746, Korea.
Hosung
H
Seo
Laboratorie CRISMAT, CNRS UMR 6508, ENSICAEN, Normandie Universite, 6 Bd Marechal Juin, F-14050 Caen Cedex 4, France.
Morgane
M
Lacotte
Laboratorie CRISMAT, CNRS UMR 6508, ENSICAEN, Normandie Universite, 6 Bd Marechal Juin, F-14050 Caen Cedex 4, France.
Adrian
A
David
Department of Nanomaterials Engineering, Chungnam National University, Daejeon. 305-764, Korea.
Hyun You
HY
Kim
Laboratorie CRISMAT, CNRS UMR 6508, ENSICAEN, Normandie Universite, 6 Bd Marechal Juin, F-14050 Caen Cedex 4, France.
Wilfrid
W
Prellier
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon. 440-746, Korea.
Yunseok
Y
Kim
Department of Physics, Sungkyunkwan University, Suwon. 440-746, Korea.
Woo Seok
WS
Choi