@article{oai:nagoya.repo.nii.ac.jp:00010164,
 author = {Huang, Rong and Mizoguchi, Teruyasu and Sugiura, Kenji and Ohta, Hiromichi and Koumoto, Kunihito and Hirayama, Tsukasa and Ikuhara, Yuichi},
 journal = {APPLIED PHYSICS LETTERS},
 month = {Nov},
 note = {Ca-ion superstructures such as sqrt(3)a×sqrt(3)a (hexagonal) and 2a×sqrt(3)a (orthorhombic) in layered Ca_0.33CoO_2 crystalline film, which were prepared by the reactive solid-phase epitaxy and the subsequent ion-exchange treatment, were directly distinguished by using spherical-aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The fluctuation of Ca intensities in the HAADF-STEM image indicates the existence of many Ca vacancies in the 2a×sqrt(3)a orthorhombic superstructure, which is consistent with the partial occupation of Ca (x=0.33) in the cation sites of x=0.5.},
 pages = {181907--181907},
 title = {Direct observations of Ca ordering in Ca_0.33CoO_2 thin films with different superstructures},
 volume = {93},
 year = {2008}
}