Modulated Structure of Bi1.8Sr2.0Rh1.6Ox


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We have investigated the modulated structure of the misfit-layered crystal Bi1.8Sr2.0Rh1.6Ox by means of electron diffraction and high-resolution electron microscopy. This compound consists of two interpenetrating subsystems of a hexagonal RhO2 sheet and a distorted four-layered rock-salt-type (Bi,Sr)O block. Both subsystems have common a-, c-axes and β-angles with a = 5.28 Å, c = 29.77 Å and β = 93.7º. On the other hand, the crystal structure is incommensurated parallel to the b-axes, among which b1 = 3.07 Å for the RhO2 sheet and b2 = 4.88 Å for the (Bi,Sr)O block. The misfit ratio, b1/b2 ~ 0.63, characterizes the structural analogue as [Bi1.79Sr1.98Oy]0.63[RhO2]. This compound has two modulation vectors, i.e., q1 = – a* + 0.63b1* and q2 = 0.17b1* + c*, and the superspace group is assigned as the Cc(1β0, 0μ1)-type from the electron diffraction patterns. High-resolution images taken with the incident electron beam parallel to the a- and c-axes clearly show displacive as well as compositional modulations.



Key Engineering Materials (Volumes 336-338)

Edited by:

Wei Pan and Jianghong Gong




K. Yubuta et al., "Modulated Structure of Bi1.8Sr2.0Rh1.6Ox", Key Engineering Materials, Vols. 336-338, pp. 818-821, 2007

Online since:

April 2007




[1] H. Leligny et al.: Acta Cryst. B Vol. 56 (2000), p.173.

[2] S. Okada et al.: Jpn. J. Appl. Phys. Vol. 44 (2005), p.1834.

[3] Y. Miyazaki et al.: Jpn. J. Appl. Phys. Vol. 42 (2003), p.7467.

[4] K. Yubuta et al.: Jpn. J. Appl. Phys. (in press).

[5] A. Yamamoto: Acta Cryst. A Vol. 52 (1996), p.509.

[6] Y. Matsui et al.: Jpn. J. Appl. Phys. Vol. 27 (1988), pp. L372.