Conductive
Nature of Grain Boundaries in Nanocrystalline Stabilized Bi<sub>2</sub>O<sub>3</sub> Thin-Film Electrolyte
Seung
Jin Jeong
No Woo Kwak
Pilgyu Byeon
Sung-Yoon Chung
WooChul Jung
10.1021/acsami.7b16875.s001
https://acs.figshare.com/articles/journal_contribution/Conductive_Nature_of_Grain_Boundaries_in_Nanocrystalline_Stabilized_Bi_sub_2_sub_O_sub_3_sub_Thin-Film_Electrolyte/5864139
Stabilized Bi<sub>2</sub>O<sub>3</sub> has gained a considerable amount of attention
as a solid electrolyte material for low-temperature solid oxide fuel
cells due to its superior oxygen-ion conductivity at the temperature
of relevance (≤500 °C). Despite many research efforts
to measure the transport properties of stabilized Bi<sub>2</sub>O<sub>3</sub>, the effects of grain boundaries on the electrical conductivity
have rarely been reported and their results are even controversial.
Here, we attempt quantitatively to assess the grain boundary contribution
out of the total ionic conductivity at elevated temperatures (350–500
°C) by fabricating epitaxial and nano-polycrystalline thin films
of yttrium-stabilized Bi<sub>2</sub>O<sub>3</sub>. Surprisingly, both
epitaxial and polycrystalline films show nearly identical levels of
ionic conductivity, as measured by alternating current impedance spectroscopy
and this is the case despite the fact that the polyfilm possesses
nanosized columnar grains and thus an extremely high density of the
grain boundaries. The highly conductive nature of grain boundaries
in stabilized Bi<sub>2</sub>O<sub>3</sub> is discussed in terms of
the clean and chemically uniform grain boundary without segregates,
and the implications for device application are suggested.
2018-01-25 00:00:00
yttrium-stabilized Bi 2 O 3
uniform grain boundary
oxide fuel cells
conductivity
nanosized columnar grains
Bi 2 O 3
grain boundary contribution
Nanocrystalline Stabilized Bi 2 O 3 Thin-Film Electrolyte Stabilized Bi 2 O 3
grain boundaries