ISSN:
1600-5740
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
Notes:
The room-temperature crystal structure of the B-site ordered complex perovskite strontium ytterbium niobate, Sr(Yb0.5Nb0.5)O3 [monoclinic, Z = 2, P21/n (set 2), a = 5.79095 (8), b = 5.82210 (7), c = 8.20358 (12) Å, β = 90.126 (1)°, with final Rwp = 0.0595, RBragg = 0.0203 for the neutron profile and Rwp = 0.0832, RBragg = 0.0193 for the X-ray profile, respectively], was determined by X-ray powder diffraction, high-resolution neutron powder diffraction and transmission electron microscopy. This compound shows a slight triclinic distortion from the prototype doubled cubic perovskite cell as a result of an a−a−c+-type oxygen octahedral tilting distortion. It is also shown that the site ordering of the different species of B-site cations, Yb3+ and Nb5+, inherently leads to a difference between the volumes of the YbO6 and NbO6 octahedra. This volume difference is shown to inevitably inhibit the rigid rotation of octahedra.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0108768198018333
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