The air-sintering characteristics and electrical conductivity of (Sr1−xLax)TiO3 perovskites (0 ≤ x ≤ 0.3) synthesized by the citric acid method were evaluated in terms of their use as interconnect materials in solid oxide fuel cells. A single perovskite phase of (Sr0.8La0.2)TiO3 powder was formed at 800 °C. In this powder, a Ruddlesden–Popper Sr2TiO4 layer appeared in the temperature range of 1100–1500 °C, and disappeared at 1600 °C. (Sr0.8La0.2)TiO3 powders which were calcined at 1000–1100 °C showed the best sintering characteristics. The relative density of the samples reached 94% at 1400 °C, although the Ruddlesden–Popper layer remained in this dense sample. Electrical conductivities of (Sr1−xLax)TiO3 bars at 1000 °C were approximately 0.10–1.1 S cm−1 in air and 7.1–12 S cm−1 in a reducing atmosphere. For a (Sr0.9La0.1)TiO3 pellet placed between both air and reducing atmospheres, the conductivity at 850 °C was 0.033 S cm−1, which is close to that in air. No compositional dependency on electrical conductivity was observed for the (Sr1−xLax)TiO3 pellets.

References

References
1.
Minh
,
N. Q.
, 1993, “
Ceramic Fuel Cells
,”
J. Am. Ceram. Soc.
,
76
(
3
), pp.
563
588
.
2.
Chan
,
N.-H.
,
Sharma
,
R. K.
, and
Smyth
,
D. M.
, 1981 “
Nonstoichiomery in SrTiO3
,”
J. Electrochem. Soc.
,
128
(
8
), pp.
1762
1769
.
3.
Tsukuda
,
H.
,
Okuma
,
S.
, and
Tomida
,
K.
, 2009, “
Influence of La Substitute on Sintering Behavior, Electronic Properties and Thermal Expansion of Sr11.5xLaxTiO3
,”
J. Jpn. Soc. Powder Powder Metall.
,
56
(
2
), pp.
65
70
.
4.
Tomida
,
K.
,
Yamashita
,
A.
,
Tukuda
,
H.
,
Kabata
,
T.
,
Ikeda
,
K.
,
Hisatome
,
N.
, and
Yamazaki
,
Y.
, 2009, “
Optimization of Segmented-in-Series Tubular SOFCs With an (La, Sr)CoO3 System Cathode and the Generation Characteristics Under Pressurization
,”
Electrochemistry (Tokyo, Jpn.)
,
77
(
12
), pp.
1018
1027
.
5.
Hui
,
S.
, and
Petric
,
A.
, 2002, “
Evaluation of Yttrium-Doped SrTiO3 as an Anode for Solid Oxide Fuel Cells
,”
J. Eur. Ceram. Soc.
,
22
, pp.
1673
1681
.
6.
Hui
,
S.
, and
Petric
,
A.
, 2002, “
Electrical Property of Yttrium-Doped Strontium Titanate Under Reducing Conditions
,”
J. Electrochem. Soc.
,
149
(
1
), pp.
J1
J10
.
7.
Fu.
,
Q. X.
,
S. B.
Mi
,
Wessel
E.
, and
Tietz
,
F.
, 2008, “
Influence of Sintering Conditions on Microstructure and Electrical Conductivity Yttrium-Substituted SrTiO3
,”
J. Eur. Ceram. Soc.
,
28
, pp.
881
820
.
8.
Blennow
,
P.
,
Hagen
,
A.
,
Hansen
,
K. K.
,
Wallenberg
,
L. R.
, and
Mogensen
,
M.
, 2008, “
Synthesis of Nb-Doped SrTiO3 by a Modified Glycine-Nitrate Process
,”
J. Eur. Ceram. Soc.
,
27
, pp.
3609
3612
.
9.
Blennow
,
P.
,
Hansen
,
K. K.
,
Wallenberg
,
L. R.
, and
Mogensen
,
M.
, 2007, “
Defect and Electrical Transport of Nb-Doped SrTiO3
.”
Solid State Ionics
,
179
, pp.
2047
2058
.
10.
Flandermeyer
,
B. F.
,
Aganwal
,
A. K.
, and
Anderson
,
H. U.
, 1984, “
Oxygen-Reduction Behavior of La-Doped SrTiO3
,”
J. Mater. Sci.
,
19
, pp.
2593
2598
.
11.
Moos
,
R.
, and
Härdtl
,
K. H.
, 1996, “
Electronic Transport Properties of Sr1xLaxTiO3 Ceramics
,”
J. Appl. Phys.
,
80
(
1
), pp.
393
400
.
12.
Balachandran
U.
, and
Eror
,
N. G.
, 1982, “
Electrical Conductivity in Lanthanum-Doped Strontium Titanate
,”
J. Electrochem. Soc.
,
129
(
5
), pp.
1021
1026
.
13.
Li
,
X.
,
Zhao
,
N.
,
Xu
,
N.
,
Zhou
,
X.
,
Zhang
,
C.
, and
Chen
,
N.
, 2009, “
Electrical Conduction Behaviour of La, Co co-Doped SrTiO3 Perovskite as Anode Material for Solid Oxide Fuel Cells
,”
Int. J. Hydrogen Energy
,
34
, pp.
6407
6414
.
14.
Li
,
X.
,
Zhao
,
H.
,
Zhou
,
X.
,
Xu
,
N.
,
Xie
,
Z.
, and
Chen
,
N.
, 2010, “
Electrical Conductivity and Structural Stability of La-Doped SrTiO3 With A-Site Deficiency as Anode Materials for Solid Oxide Fuel Cells
,”
Int. J. Hydrogen Energy
,
35
, pp.
7913
7918
.
15.
Marina
,
O. A.
,
Canfield
,
N. L.
, and
Stevenson
,
J. W.
, 2002, “
Thermal, Electrical and Electrocatalytical Properties of Lanthanum-Doped Strontium Titanate
,”
Solid State Ionics
,
149
, pp.
21
28
.
16.
Wang
,
Z.
,
Mori
M.
, and
Itoh
,
T.
, 2010, “
Thermal Expansion Properties of Sr1xLaxTiO3 (0≤x≤0.3) Perovskites in Oxidizing and Reducing Atmospheres
,”
J. Electrochem. Soc.
,
157
(
12
), pp.
B1783
B1789
.
17.
Mori
,
M.
, and
Wang
,
Z.
, 2010, “
Pore Formation During Sintering Process of (Sr0.9La0.1)1xTi1yO3+δ Perovskites (x, y=0, 0.04) Synthesized by the Citric Acid Method
,”
Electrochemistry
,
78
(
11
). pp.
896
899
.
18.
Navas
,
C.
, and
Loye
,
H.-C.
, 1997, “
Conductivity Studies on Oxygen Deficient Ruddlesden–Popper Phase
,”
Solid State Ionics
,
93
, pp.
171
176
.
19.
Mori
,
M.
, and
Itoh
,
T.
, 2011, “
Anomalous Sintering Behavior of (Sr0.7La0.3)1xTiO3 Perovskites (0≤x≤0.12) Synthesized by the Pechini Method
,”
ECS Trans.
(accepted).
20.
Kröger
,
F. A.
, and
Vink
,
J. J.
, 1956, “
Solid State Physics
,”
F.
Seitz
, and
D.
Turnbull
, eds.,
Academic
,
New York
, pp.
307
435
.
21.
Slater
,
P. R.
,
Fagg
,
D. P.
, and
Irvine
,
J. T.
, 1997, “
Synthesis and Electrical Characterisation of Doped Perovskite Titanates as Anode Potential Materials for Solid Oxide Fuel Cells
,”
J. Mater. Chem.
,
7
(
12
), pp.
2495
2498
.
22.
Waser
,
R
, 1995, “
Electronic Properties of Grain Boundaries in SrTiO3 and BaTiO3 Ceramics
,”
Solid State Ionics
,
75
, pp.
89
99
.
23.
Abrant
,
J. C. C.
,
Labricha
,
J. A.
, and
Frade
,
J. R.
, 2002, “
Behaviour of Strontium Titanate Ceramics in Reducing Conditions Suggesting Enhanced Conductivity Along Grain Contact
,”
J. Euro. Ceram. Soc.
,
22
, pp.
1683
1691
.
You do not currently have access to this content.