In:
Japanese Journal of Applied Physics, IOP Publishing, Vol. 39, No. 9S ( 2000-09-01), p. 5711-
Abstract:
The crystal structure of Bi-layered perovskite Sr 0.85 Bi 2.1 Ta 2 O 9 was determined at 750 K by X-ray Rietveld analysis. Sr 0.85 Bi 2.1 Ta 2 O 9 with space group A2 1 am at room temperature transforms to the paraelectric phase above 670 K, passing through a probable intermediate state at 510 K. Assuming two possible orthorhombic Fmmm and tetragonal I4/mmm space groups, analysis of the crystal structure of the paraelectric phase gave the final discrepancy factors R w p of 11.3% and 9.9%, respectively. Examination of possible reflections and peak positions at high-angles proved that the true space group is I4/mmm for the high temperature paraelectric phase. The lattice constants are a =3.927 (1), c =25.142 (1) Å at 750 K. The TaO 6 octahedron is not perfect and is slightly distorted along the c -axis, having the dipole moment of 0.478 debye.
Type of Medium:
Online Resource
ISSN:
0021-4922
,
1347-4065
DOI:
10.1143/JJAP.39.5711
Language:
Unknown
Publisher:
IOP Publishing
Publication Date:
2000
detail.hit.zdb_id:
218223-3
detail.hit.zdb_id:
797294-5
detail.hit.zdb_id:
2006801-3
detail.hit.zdb_id:
797295-7
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