Nanograin composite model studies of nanocrystalline gadolinia-doped ceria

Ted C. Yeh, Nicola H. Perry, Thomas O Mason

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Nanocrystalline gadolinia-doped ceria (GDC) specimens with grain sizes ranging from 10 to 100 nm were studied by AC-impedance spectroscopy over the temperature range of ∼150°- ∼ 300°C, and were analyzed by the nanograin composite model (n-GCM), which is capable of extracting local properties (grain-core conductivity, grain-boundary conductivity, grain-boundary dielectric constant) and also grain-boundary width. The grain-core dielectric constant, a necessary input parameter for the n-GCM procedure, was measured separately on a microcrystalline GDC specimen sintered from identical powders. In spite of modest increases in grain-boundary conductivity at the nanoscale, the total conductivity exhibited a monotonic decrease with decreasing grain size. This behavior was attributed to the large increase in the number of grain-boundary barriers at the nanoscale, which overwhelms the slight increase in grain-boundary conductivity. An unusual "up-and-down" behavior was observed in grain-boundary conductivity versus grain size, which was accounted for by a similar trend in the preexponential factor versus grain size. Effective grain-boundary widths, also determined by the n-GCM, exhibited a similar "up-and-down" behavior, which probably reflects the differences in thermal history from specimen-to-specimen.

Original languageEnglish
Pages (from-to)1073-1078
Number of pages6
JournalJournal of the American Ceramic Society
Volume94
Issue number4
DOIs
Publication statusPublished - Apr 2011

Fingerprint

Gadolinium
Cerium compounds
Grain boundaries
Composite materials
Permittivity
gadolinium oxide
Powders
Spectroscopy

ASJC Scopus subject areas

  • Ceramics and Composites
  • Materials Chemistry

Cite this

Nanograin composite model studies of nanocrystalline gadolinia-doped ceria. / Yeh, Ted C.; Perry, Nicola H.; Mason, Thomas O.

In: Journal of the American Ceramic Society, Vol. 94, No. 4, 04.2011, p. 1073-1078.

Research output: Contribution to journalArticle

@article{e3cecc7dad764ae2ac4351401c5e6909,
title = "Nanograin composite model studies of nanocrystalline gadolinia-doped ceria",
abstract = "Nanocrystalline gadolinia-doped ceria (GDC) specimens with grain sizes ranging from 10 to 100 nm were studied by AC-impedance spectroscopy over the temperature range of ∼150°- ∼ 300°C, and were analyzed by the nanograin composite model (n-GCM), which is capable of extracting local properties (grain-core conductivity, grain-boundary conductivity, grain-boundary dielectric constant) and also grain-boundary width. The grain-core dielectric constant, a necessary input parameter for the n-GCM procedure, was measured separately on a microcrystalline GDC specimen sintered from identical powders. In spite of modest increases in grain-boundary conductivity at the nanoscale, the total conductivity exhibited a monotonic decrease with decreasing grain size. This behavior was attributed to the large increase in the number of grain-boundary barriers at the nanoscale, which overwhelms the slight increase in grain-boundary conductivity. An unusual {"}up-and-down{"} behavior was observed in grain-boundary conductivity versus grain size, which was accounted for by a similar trend in the preexponential factor versus grain size. Effective grain-boundary widths, also determined by the n-GCM, exhibited a similar {"}up-and-down{"} behavior, which probably reflects the differences in thermal history from specimen-to-specimen.",
author = "Yeh, {Ted C.} and Perry, {Nicola H.} and Mason, {Thomas O}",
year = "2011",
month = "4",
doi = "10.1111/j.1551-2916.2010.04200.x",
language = "English",
volume = "94",
pages = "1073--1078",
journal = "Journal of the American Ceramic Society",
issn = "0002-7820",
publisher = "Wiley-Blackwell",
number = "4",

}

TY - JOUR

T1 - Nanograin composite model studies of nanocrystalline gadolinia-doped ceria

AU - Yeh, Ted C.

AU - Perry, Nicola H.

AU - Mason, Thomas O

PY - 2011/4

Y1 - 2011/4

N2 - Nanocrystalline gadolinia-doped ceria (GDC) specimens with grain sizes ranging from 10 to 100 nm were studied by AC-impedance spectroscopy over the temperature range of ∼150°- ∼ 300°C, and were analyzed by the nanograin composite model (n-GCM), which is capable of extracting local properties (grain-core conductivity, grain-boundary conductivity, grain-boundary dielectric constant) and also grain-boundary width. The grain-core dielectric constant, a necessary input parameter for the n-GCM procedure, was measured separately on a microcrystalline GDC specimen sintered from identical powders. In spite of modest increases in grain-boundary conductivity at the nanoscale, the total conductivity exhibited a monotonic decrease with decreasing grain size. This behavior was attributed to the large increase in the number of grain-boundary barriers at the nanoscale, which overwhelms the slight increase in grain-boundary conductivity. An unusual "up-and-down" behavior was observed in grain-boundary conductivity versus grain size, which was accounted for by a similar trend in the preexponential factor versus grain size. Effective grain-boundary widths, also determined by the n-GCM, exhibited a similar "up-and-down" behavior, which probably reflects the differences in thermal history from specimen-to-specimen.

AB - Nanocrystalline gadolinia-doped ceria (GDC) specimens with grain sizes ranging from 10 to 100 nm were studied by AC-impedance spectroscopy over the temperature range of ∼150°- ∼ 300°C, and were analyzed by the nanograin composite model (n-GCM), which is capable of extracting local properties (grain-core conductivity, grain-boundary conductivity, grain-boundary dielectric constant) and also grain-boundary width. The grain-core dielectric constant, a necessary input parameter for the n-GCM procedure, was measured separately on a microcrystalline GDC specimen sintered from identical powders. In spite of modest increases in grain-boundary conductivity at the nanoscale, the total conductivity exhibited a monotonic decrease with decreasing grain size. This behavior was attributed to the large increase in the number of grain-boundary barriers at the nanoscale, which overwhelms the slight increase in grain-boundary conductivity. An unusual "up-and-down" behavior was observed in grain-boundary conductivity versus grain size, which was accounted for by a similar trend in the preexponential factor versus grain size. Effective grain-boundary widths, also determined by the n-GCM, exhibited a similar "up-and-down" behavior, which probably reflects the differences in thermal history from specimen-to-specimen.

UR - http://www.scopus.com/inward/record.url?scp=79953704495&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79953704495&partnerID=8YFLogxK

U2 - 10.1111/j.1551-2916.2010.04200.x

DO - 10.1111/j.1551-2916.2010.04200.x

M3 - Article

AN - SCOPUS:79953704495

VL - 94

SP - 1073

EP - 1078

JO - Journal of the American Ceramic Society

JF - Journal of the American Ceramic Society

SN - 0002-7820

IS - 4

ER -