Crystal structure of the parent misfit-layered cobalt oxide [Sr2O2]qCoO2

T. Nagai; K. Sakai; M. Karppinen; T. Asaka; K. Kimoto; A. Yamazaki; H. Yamauchi; Y. Matsui

doi:10.1016/j.jssc.2006.03.016

Crystal structure of the parent misfit-layered cobalt oxide [Sr₂O₂]_qCoO₂

T. Nagai^*, K. Sakai, M. Karppinen, T. Asaka, K. Kimoto, A. Yamazaki, H. Yamauchi, Y. Matsui

^*Corresponding author for this work

School of Creative Science and Engineering

Research output: Contribution to journal › Article › peer-review

13 Citations (Scopus)

Abstract

The crystal structure of our newly discovered Sr-Co-O phase is investigated in detail through high-resolution electron microscopy (HREM) techniques. Electron diffraction (ED) measurement together with energy dispersive X-ray spectroscopy (EDS) analysis show that an ampoule-synthesized sample contains an unknown Sr-Co-O ternary phase with monoclinic symmetry and the cation ratio of Sr/Co=1. From HREM images a layered structure with a regular stacking of a CdI₂-type CoO₂ sheet and a rock-salt-type Sr₂O₂ double-layered block is observed, which confirms that the phase is the parent of the more complex "misfit-layered (ML)" cobalt oxides of [M_mA₂O_m+2]_qCoO₂ with the formula of [Sr₂O₂]_qCoO₂, i.e. m = 0. It is revealed that the misfit parameter q is 0.5, i.e. the two sublattices of the CoO₂ sheet and the Sr₂O₂ block coexist to form a commensurate composite structure. We propose a structural model with monoclinic P2₁/m symmetry, which is supported by simulations of ED patterns and HREM images based on dynamical diffraction theory.

Original language	English
Pages (from-to)	1898-1903
Number of pages	6
Journal	Journal of Solid State Chemistry
Volume	179
Issue number	6
DOIs	https://doi.org/10.1016/j.jssc.2006.03.016
Publication status	Published - 2006 Jun

Keywords

Electron diffraction
High resolution electron microscopy
Misfit-layered cobalt oxide
Strontium cobalt oxide
Thermoelectric material
Transmission electron microscopy

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Ceramics and Composites
Condensed Matter Physics
Physical and Theoretical Chemistry
Inorganic Chemistry
Materials Chemistry

Access to Document

10.1016/j.jssc.2006.03.016

Cite this

@article{ca3c09eb434748f28986f7237ec01fb1,

title = "Crystal structure of the parent misfit-layered cobalt oxide [Sr2O2]qCoO2",

abstract = "The crystal structure of our newly discovered Sr-Co-O phase is investigated in detail through high-resolution electron microscopy (HREM) techniques. Electron diffraction (ED) measurement together with energy dispersive X-ray spectroscopy (EDS) analysis show that an ampoule-synthesized sample contains an unknown Sr-Co-O ternary phase with monoclinic symmetry and the cation ratio of Sr/Co=1. From HREM images a layered structure with a regular stacking of a CdI2-type CoO2 sheet and a rock-salt-type Sr2O2 double-layered block is observed, which confirms that the phase is the parent of the more complex {"}misfit-layered (ML){"} cobalt oxides of [MmA2Om+2]qCoO2 with the formula of [Sr2O2]qCoO2, i.e. m = 0. It is revealed that the misfit parameter q is 0.5, i.e. the two sublattices of the CoO2 sheet and the Sr2O2 block coexist to form a commensurate composite structure. We propose a structural model with monoclinic P21/m symmetry, which is supported by simulations of ED patterns and HREM images based on dynamical diffraction theory.",

keywords = "Electron diffraction, High resolution electron microscopy, Misfit-layered cobalt oxide, Strontium cobalt oxide, Thermoelectric material, Transmission electron microscopy",

author = "T. Nagai and K. Sakai and M. Karppinen and T. Asaka and K. Kimoto and A. Yamazaki and H. Yamauchi and Y. Matsui",

note = "Funding Information: We thank M. Owada and C. Tsuruta for specimen preparations and discussions. This work was supported by the Nanotechnology Support Project of the MEXT, Japan, and also by Grants-in-aid for Scientific Research (Nos. 15206002 and 15206071) from the Japan Society for the Promotion of Science. M.K. acknowledges the financial support from the Academy of Finland (Decision No. 110433). ",

year = "2006",

month = jun,

doi = "10.1016/j.jssc.2006.03.016",

language = "English",

volume = "179",

pages = "1898--1903",

journal = "Journal of Solid State Chemistry",

issn = "0022-4596",

publisher = "Academic Press Inc.",

number = "6",

}

TY - JOUR

T1 - Crystal structure of the parent misfit-layered cobalt oxide [Sr2O2]qCoO2

AU - Nagai, T.

AU - Sakai, K.

AU - Karppinen, M.

AU - Asaka, T.

AU - Kimoto, K.

AU - Yamazaki, A.

AU - Yamauchi, H.

AU - Matsui, Y.

N1 - Funding Information: We thank M. Owada and C. Tsuruta for specimen preparations and discussions. This work was supported by the Nanotechnology Support Project of the MEXT, Japan, and also by Grants-in-aid for Scientific Research (Nos. 15206002 and 15206071) from the Japan Society for the Promotion of Science. M.K. acknowledges the financial support from the Academy of Finland (Decision No. 110433).

PY - 2006/6

Y1 - 2006/6

N2 - The crystal structure of our newly discovered Sr-Co-O phase is investigated in detail through high-resolution electron microscopy (HREM) techniques. Electron diffraction (ED) measurement together with energy dispersive X-ray spectroscopy (EDS) analysis show that an ampoule-synthesized sample contains an unknown Sr-Co-O ternary phase with monoclinic symmetry and the cation ratio of Sr/Co=1. From HREM images a layered structure with a regular stacking of a CdI2-type CoO2 sheet and a rock-salt-type Sr2O2 double-layered block is observed, which confirms that the phase is the parent of the more complex "misfit-layered (ML)" cobalt oxides of [MmA2Om+2]qCoO2 with the formula of [Sr2O2]qCoO2, i.e. m = 0. It is revealed that the misfit parameter q is 0.5, i.e. the two sublattices of the CoO2 sheet and the Sr2O2 block coexist to form a commensurate composite structure. We propose a structural model with monoclinic P21/m symmetry, which is supported by simulations of ED patterns and HREM images based on dynamical diffraction theory.

AB - The crystal structure of our newly discovered Sr-Co-O phase is investigated in detail through high-resolution electron microscopy (HREM) techniques. Electron diffraction (ED) measurement together with energy dispersive X-ray spectroscopy (EDS) analysis show that an ampoule-synthesized sample contains an unknown Sr-Co-O ternary phase with monoclinic symmetry and the cation ratio of Sr/Co=1. From HREM images a layered structure with a regular stacking of a CdI2-type CoO2 sheet and a rock-salt-type Sr2O2 double-layered block is observed, which confirms that the phase is the parent of the more complex "misfit-layered (ML)" cobalt oxides of [MmA2Om+2]qCoO2 with the formula of [Sr2O2]qCoO2, i.e. m = 0. It is revealed that the misfit parameter q is 0.5, i.e. the two sublattices of the CoO2 sheet and the Sr2O2 block coexist to form a commensurate composite structure. We propose a structural model with monoclinic P21/m symmetry, which is supported by simulations of ED patterns and HREM images based on dynamical diffraction theory.

KW - Electron diffraction

KW - High resolution electron microscopy

KW - Misfit-layered cobalt oxide

KW - Strontium cobalt oxide

KW - Thermoelectric material

KW - Transmission electron microscopy

UR - http://www.scopus.com/inward/record.url?scp=33646871561&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33646871561&partnerID=8YFLogxK

U2 - 10.1016/j.jssc.2006.03.016

DO - 10.1016/j.jssc.2006.03.016

M3 - Article

AN - SCOPUS:33646871561

SN - 0022-4596

VL - 179

SP - 1898

EP - 1903

JO - Journal of Solid State Chemistry

JF - Journal of Solid State Chemistry

IS - 6

ER -