Abstract
Structures of some phases in the SrMnO3−x system accompanied by planar defect were studied using a high resolution electron microscope. A four-layer structure with a hexagonal unit cell was found to have an oxygen deficiency in some degree followed by planar defects normal to the c-axis which are classified into several types. On the basis of observed images showing an irregular stacking along the c-axis in the hexagonal unit, the distribution and the origin of the planar defect are discussed. A structure image showed the transformation of the four-layer phase into a nonstoichiometric state and a shear structure with a displacement vector of i occurring between the face-sharing octahedra. Experiment by in situ observation during beam irradiation in an electron microscope indicates the process of the formation of the planar defect. A mechanism for the formation of the planar defect is proposed by which oxygen deficiency in face-sharing octahedra induces the displacement of SrO3 layers and oxygen octahedra which reduce the coordination number of Mn ions and the disruption of face-sharing octahedra.
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References
Y. Syono, S. Akimoto, and K. Kohn, J. Phys. Soc. Jpn. 26, 993 (1969).
T. Negas and R. S. Roth, J. Solid State Chem. 3, 323 (1971).
B. L. Chamberland, A.W. Sleight, and J. F. Weiher, J. Solid State Chem. 1, 507 (1970).
A. Hardy, Acta Crystallogr. Sect. B15, 179 (1962).
T. Negas and R. S. Roth, J. Solid State Chem. 1, 409 (1970).
V. Caignaert, M. Hervieu, N. Nguyen, and B. Raveau, J. Solid State Chem. 62, 281 (1986).
H. Shibahara and H. Hashimoto, in Proc. 7th Int. Conf. on Crystal Growth, Stuttgart, J. Cryst. Growth65, 683 (1983).
H. Shibahara, J. Solid State Chem. 69, 81 (1987).
H. Shibahara, J. Solid State Chem. 66, 116 (1987).
H. Shibahara, J. Solid State Chem. 81, 40 (1989).
M. Mizutani, V. Okura, A. Kitazawa, and M. Kato, J. Chem. Soc. Jpn. Ind. Chem. Soc. 73, 1103 (1970).
J. M. Cowely and A. F. Moodie, Acta Crystallogr. 10, 609 (1957).
P. Goodman and A. F. Moodie, Acta Crystallogr. Sect. A30, 280 (1974).
R. D. Shannon and C.T. Prewitt, Acta Crystallogr. Sect. B25, 925 (1969).
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Shibahara, H. Electron microscope study of the structure of SrMnO3−x with planar defect. Journal of Materials Research 6, 565–573 (1991). https://doi.org/10.1557/JMR.1991.0565
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DOI: https://doi.org/10.1557/JMR.1991.0565