TY - JOUR
T1 - The exceptionally large height of the potential barrier at the grain boundary of a LaGaO3-based solid solution deduced from a linear diffusion model
AU - Chang, Chih Yuan S.
AU - Lubomirsky, Igor
AU - Kim, Sangtae
N1 - Funding Information:
The authors thank the US–Israel Binational Science Foundation (2016006) for funding this research. The research is also made possible in part by the generosity of the Harold Perlman Family.
PY - 2018
Y1 - 2018
N2 - The extent of the influence of space charge on the electric current through the grain boundary in solid electrolytes can be parameterized by the grain boundary potential, i.e. the height of the potential barrier formed at the grain boundary. Previously the value of this parameter has been estimated exclusively by the ratio of the grain boundary resistivity to the bulk counterpart over several decades. We recently demonstrated that it can be alternatively determined by analyzing the current-voltage characteristic of the grain boundary. Furthermore, we theoretically justified that the conventional method is in fact a subset of the new method, therefore, the latter is a more reliable and comprehensive approach to determine the grain boundary potential. Here, we present the experimental results that verify our theoretical justification. The values of the grain boundary potential determined for 1 mol% Sr-doped LaGaO3 (LSG1) employing both methods are in excellent agreement with one another. Such a consistency has not been reported for other solid electrolytes to date and we provide an explanation for it. Our data also indicate that for the case of LSG1, the Nernst-Einstein relation is preserved at the electric field exceeding 900 kV cm-1.
AB - The extent of the influence of space charge on the electric current through the grain boundary in solid electrolytes can be parameterized by the grain boundary potential, i.e. the height of the potential barrier formed at the grain boundary. Previously the value of this parameter has been estimated exclusively by the ratio of the grain boundary resistivity to the bulk counterpart over several decades. We recently demonstrated that it can be alternatively determined by analyzing the current-voltage characteristic of the grain boundary. Furthermore, we theoretically justified that the conventional method is in fact a subset of the new method, therefore, the latter is a more reliable and comprehensive approach to determine the grain boundary potential. Here, we present the experimental results that verify our theoretical justification. The values of the grain boundary potential determined for 1 mol% Sr-doped LaGaO3 (LSG1) employing both methods are in excellent agreement with one another. Such a consistency has not been reported for other solid electrolytes to date and we provide an explanation for it. Our data also indicate that for the case of LSG1, the Nernst-Einstein relation is preserved at the electric field exceeding 900 kV cm-1.
UR - http://www.scopus.com/inward/record.url?scp=85044732693&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85044732693&partnerID=8YFLogxK
U2 - 10.1039/c7cp08223a
DO - 10.1039/c7cp08223a
M3 - Article
C2 - 29536998
AN - SCOPUS:85044732693
VL - 20
SP - 8719
EP - 8723
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
SN - 1463-9076
IS - 13
ER -