Ba 3 YRu 0.73(2) Al 1.27(2) O 8 and Ba 5 Y 2 Ru 1.52(2) Al 1.47(2) O 13.5 : New Perovskite Ruthenates with Partial Octahedra Replacement

• Published in: Zeitschrift für Naturforschung. B, A journal of chemical sciences Vol. 62; no. 11; pp. 1383 - 1389
• Main Authors: Schüpp-Niewaa, Barbara, Shlyk, Larysa, Prots, Yurii, Krabbes, Gernot, Niewa, Rainer
• Format: Journal Article
• Language: English
• Published: 01-11-2007
• ISSN: 0932-0776; 1865-7117
• DOI: 10.1515/znb-2007-1106

Dark red single crystals of the new phases Ba
3
YRu
0.73(2)
Al
1.27(2)
O
8
and Ba
5
Y
2
Ru
1.52(2)
Al
1.47(2)
O
13.5
have been grown from powder mixtures of BaCO
3
, Y
2
O
3
, Al
2
O
3
, and RuO
2
. The compositions given in the formulas result from the refinements of the crystal structures based on single crystal X-ray diffraction data (hexagonal P6
3
/mmc (No. 194), Z = 2, Ba
3
YRu
0.73(2)
Al
1.27(2)
O
8
: a = 5.871(1), c = 14.633(3) Å , R1 = 0.035, wR2 = 0.069 and Ba
5
Y
2
Ru
1.52(2)
Al
1.47(2)
O
13.5
: a = 5.907(1), c = 24.556(5) Å, R1 = 0.057, wR2 = 0.114). Ba
3
YRu
0.73(2)
Al
1.27(2)
O
8
crystallizes in a 6H perovskite structure, Ba
5
Y
2
Ru
1.52(2)
Al
1.47(2)
O
13.5
has been characterized as a 10H Perovskite. Due to similar spatial extensions of (Ru
2
O
9
) facesharing pairs of octahedra and (Al
2
O
7
) vertex-sharing pairs of tetrahedra, both structures show partial mutual substitution of these units. Consequently, the title compounds may be written as Ba
3
Y(Ru
2
O
9
)
1−x
(Al
2
O
7
)
x
, x = 0.64(1) and Ba
5
Y
2
RuO
6
(Ru
2
O
9
)
1−x
(Al
2
O
7
)
x
, x = 0.74(1). This interpretation is supported by the results of electron probe microanalysis using wavelength-dispersive X-ray spectroscopy. An oxidation state of Ru close to +5 for the (Ru
2
O
9
) units, as can be derived from the distances d(Ru-Ru), additionally leads to similar charges of both the (Ru
2
O
9
) and the (Al
2
O
7
) units.