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Crystal Structure of the Microwave Dielectric Resonator Ba 2 Ti 9 O 20
Author(s) -
TILLMANNS EKKEHART,
HOFMEISTER WOLFGANG,
BAUR WERNER H.
Publication year - 1983
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1983.tb15712.x
Subject(s) - triclinic crystal system , octahedron , crystallography , crystal structure , materials science , oxygen atom , chemistry , molecule , organic chemistry
A single‐crystal X‐ray study of dibarium nonatitanate, Ba 2 Ti 9 O 20 , yielded the triclinic space group P 1 with a =0.7471(1), b= 1.4081(2), c= 1.4344(2) nm, α=89.94(2)°, β= 79.43(2)°, γ= 84.45(2)°, V = 1.476 nm 3 Z = 4, and D x = 4.61 Mg/m 3 . A refinement of atomic coordinates and isotropic thermal parameters led to a residual of 0.03. The structure consists of hexagonally closest‐packed layers of Ba and O atoms in the sequence (hch) 3 . All Ti atoms reside in octahedral interstices of this closest packing. The various Ti coordination octahedra share only edges and corners with each other. One‐half of the Ba atoms is twelve‐coordinated by oxygen atoms, the other half is eleven‐coordinated.