The role of point defects in the mechanical behavior of doped ceria probed by nanoindentation

Roman Korobko, Seong K. Kim, Sangtae Kim, Sidney R. Cohen, Ellen Wachtel, Igor Lubomirsky

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

The influence of dopant size and oxygen vacancy concentration on the room temperature elastic modulus and creep rate of ceria doped with Pr4+, Pr3+, Lu3+, and Gd3+, is investigated using a nanoindentation technique. Measurements are conducted with both fast (15 mN s-1) and slow (0.15 mN s-1) loading modes, including a load-hold stage at 150 mN of 8 s and 30 s, respectively. Based on the data obtained using the fast loading mode, it is found that: 1) the dopant size is a primary determinant of the elastic modulus - the larger dopants (Pr3+ and Gd3+) produce lower unrelaxed moduli which are independent of the oxygen vacancy concentration. 2) The rearrangement of point defects is the major source of room temperature creep observed during load-hold. Pr 3+- and Gd3+-doped ceria display the higher creep rates: due to their large size, they repel oxygen vacancies (VO), thereby promoting the formation of O7-CeCe-VO complexes that are capable of low temperature rearrangement. Lower creep rates are observed for Pr4+- and Lu3+-doped ceria: the former has no vacancies and the latter, immobile vacancies. 3) Nanoindentation is a practical technique for identifying materials with labile point defects, which may indicate useful functionality such as high ionic conductivity, large electrostriction, and inelasticity. Nanoindentation measurements performed on ceria doped with Pr4+, Pr3+, Lu3+, Gd 3+ demonstrate that the rearrangement of point defects may be a major source of creep at room temperature. Nanoindentation is shown to be an effective technique for identifying materials with labile point defects, which may point to practical functionality such as high ionic conductivity, large electrostriction, and inelasticity.

Original languageEnglish
Pages (from-to)6076-6081
Number of pages6
JournalAdvanced Functional Materials
Volume23
Issue number48
DOIs
Publication statusPublished - Dec 23 2013

Fingerprint

Cerium compounds
Point defects
Nanoindentation
nanoindentation
point defects
Creep
Oxygen vacancies
Electrostriction
electrostriction
Doping (additives)
Ionic conductivity
ion currents
Vacancies
modulus of elasticity
room temperature
oxygen
Elastic moduli
Temperature
determinants

Keywords

  • doped ceria
  • elastic modulus
  • nanoindentation
  • point defects
  • primary creep

ASJC Scopus subject areas

  • Biomaterials
  • Electrochemistry
  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

The role of point defects in the mechanical behavior of doped ceria probed by nanoindentation. / Korobko, Roman; Kim, Seong K.; Kim, Sangtae; Cohen, Sidney R.; Wachtel, Ellen; Lubomirsky, Igor.

In: Advanced Functional Materials, Vol. 23, No. 48, 23.12.2013, p. 6076-6081.

Research output: Contribution to journalArticle

Korobko, Roman ; Kim, Seong K. ; Kim, Sangtae ; Cohen, Sidney R. ; Wachtel, Ellen ; Lubomirsky, Igor. / The role of point defects in the mechanical behavior of doped ceria probed by nanoindentation. In: Advanced Functional Materials. 2013 ; Vol. 23, No. 48. pp. 6076-6081.
@article{92a7d2ecc1f44f5c90e215fce05fb52f,
title = "The role of point defects in the mechanical behavior of doped ceria probed by nanoindentation",
abstract = "The influence of dopant size and oxygen vacancy concentration on the room temperature elastic modulus and creep rate of ceria doped with Pr4+, Pr3+, Lu3+, and Gd3+, is investigated using a nanoindentation technique. Measurements are conducted with both fast (15 mN s-1) and slow (0.15 mN s-1) loading modes, including a load-hold stage at 150 mN of 8 s and 30 s, respectively. Based on the data obtained using the fast loading mode, it is found that: 1) the dopant size is a primary determinant of the elastic modulus - the larger dopants (Pr3+ and Gd3+) produce lower unrelaxed moduli which are independent of the oxygen vacancy concentration. 2) The rearrangement of point defects is the major source of room temperature creep observed during load-hold. Pr 3+- and Gd3+-doped ceria display the higher creep rates: due to their large size, they repel oxygen vacancies (VO), thereby promoting the formation of O7-CeCe-VO complexes that are capable of low temperature rearrangement. Lower creep rates are observed for Pr4+- and Lu3+-doped ceria: the former has no vacancies and the latter, immobile vacancies. 3) Nanoindentation is a practical technique for identifying materials with labile point defects, which may indicate useful functionality such as high ionic conductivity, large electrostriction, and inelasticity. Nanoindentation measurements performed on ceria doped with Pr4+, Pr3+, Lu3+, Gd 3+ demonstrate that the rearrangement of point defects may be a major source of creep at room temperature. Nanoindentation is shown to be an effective technique for identifying materials with labile point defects, which may point to practical functionality such as high ionic conductivity, large electrostriction, and inelasticity.",
keywords = "doped ceria, elastic modulus, nanoindentation, point defects, primary creep",
author = "Roman Korobko and Kim, {Seong K.} and Sangtae Kim and Cohen, {Sidney R.} and Ellen Wachtel and Igor Lubomirsky",
year = "2013",
month = "12",
day = "23",
doi = "10.1002/adfm.201301536",
language = "English",
volume = "23",
pages = "6076--6081",
journal = "Advanced Functional Materials",
issn = "1616-301X",
publisher = "Wiley-VCH Verlag",
number = "48",

}

TY - JOUR

T1 - The role of point defects in the mechanical behavior of doped ceria probed by nanoindentation

AU - Korobko, Roman

AU - Kim, Seong K.

AU - Kim, Sangtae

AU - Cohen, Sidney R.

AU - Wachtel, Ellen

AU - Lubomirsky, Igor

PY - 2013/12/23

Y1 - 2013/12/23

N2 - The influence of dopant size and oxygen vacancy concentration on the room temperature elastic modulus and creep rate of ceria doped with Pr4+, Pr3+, Lu3+, and Gd3+, is investigated using a nanoindentation technique. Measurements are conducted with both fast (15 mN s-1) and slow (0.15 mN s-1) loading modes, including a load-hold stage at 150 mN of 8 s and 30 s, respectively. Based on the data obtained using the fast loading mode, it is found that: 1) the dopant size is a primary determinant of the elastic modulus - the larger dopants (Pr3+ and Gd3+) produce lower unrelaxed moduli which are independent of the oxygen vacancy concentration. 2) The rearrangement of point defects is the major source of room temperature creep observed during load-hold. Pr 3+- and Gd3+-doped ceria display the higher creep rates: due to their large size, they repel oxygen vacancies (VO), thereby promoting the formation of O7-CeCe-VO complexes that are capable of low temperature rearrangement. Lower creep rates are observed for Pr4+- and Lu3+-doped ceria: the former has no vacancies and the latter, immobile vacancies. 3) Nanoindentation is a practical technique for identifying materials with labile point defects, which may indicate useful functionality such as high ionic conductivity, large electrostriction, and inelasticity. Nanoindentation measurements performed on ceria doped with Pr4+, Pr3+, Lu3+, Gd 3+ demonstrate that the rearrangement of point defects may be a major source of creep at room temperature. Nanoindentation is shown to be an effective technique for identifying materials with labile point defects, which may point to practical functionality such as high ionic conductivity, large electrostriction, and inelasticity.

AB - The influence of dopant size and oxygen vacancy concentration on the room temperature elastic modulus and creep rate of ceria doped with Pr4+, Pr3+, Lu3+, and Gd3+, is investigated using a nanoindentation technique. Measurements are conducted with both fast (15 mN s-1) and slow (0.15 mN s-1) loading modes, including a load-hold stage at 150 mN of 8 s and 30 s, respectively. Based on the data obtained using the fast loading mode, it is found that: 1) the dopant size is a primary determinant of the elastic modulus - the larger dopants (Pr3+ and Gd3+) produce lower unrelaxed moduli which are independent of the oxygen vacancy concentration. 2) The rearrangement of point defects is the major source of room temperature creep observed during load-hold. Pr 3+- and Gd3+-doped ceria display the higher creep rates: due to their large size, they repel oxygen vacancies (VO), thereby promoting the formation of O7-CeCe-VO complexes that are capable of low temperature rearrangement. Lower creep rates are observed for Pr4+- and Lu3+-doped ceria: the former has no vacancies and the latter, immobile vacancies. 3) Nanoindentation is a practical technique for identifying materials with labile point defects, which may indicate useful functionality such as high ionic conductivity, large electrostriction, and inelasticity. Nanoindentation measurements performed on ceria doped with Pr4+, Pr3+, Lu3+, Gd 3+ demonstrate that the rearrangement of point defects may be a major source of creep at room temperature. Nanoindentation is shown to be an effective technique for identifying materials with labile point defects, which may point to practical functionality such as high ionic conductivity, large electrostriction, and inelasticity.

KW - doped ceria

KW - elastic modulus

KW - nanoindentation

KW - point defects

KW - primary creep

UR - http://www.scopus.com/inward/record.url?scp=84890788990&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84890788990&partnerID=8YFLogxK

U2 - 10.1002/adfm.201301536

DO - 10.1002/adfm.201301536

M3 - Article

VL - 23

SP - 6076

EP - 6081

JO - Advanced Functional Materials

JF - Advanced Functional Materials

SN - 1616-301X

IS - 48

ER -