Core-Shell Structure Formation in Nb2O5-Doped SrTiO3 by Oxygen Partial Pressure Change

A core‐shell structure was observed in SrTiO3 doped with 1.2 mol% of Nb2O5, after sintering in a reducing atmosphere (5H2‐95N2) and then in an oxidizing atmosphere (air). In undoped and Al2O3‐doped SrTiO3 specimens, no core‐shell structure formed after the same sintering treatments as those for SrTi...

Full description

Saved in:
Bibliographic Details
Published inJournal of the American Ceramic Society Vol. 81; no. 11; pp. 3016 - 3018
Main Authors Chung, Sung-Yoon, Lee, Byoung-Ki, Kang, Suk-Joong L.
Format Journal Article
LanguageEnglish
Published Westerville, Ohio American Ceramics Society 01.11.1998
Blackwell
Subjects
Applied sciences
Building materials. Ceramics. Glasses
Ceramic industries
Chemical industry and chemicals
Electrotechnical and electronic ceramics
Exact sciences and technology
Technical ceramics
Additive
Niobium Oxides
Sintering
Manufacturing
Experimental study
Microstructure
Oxide ceramics
Strontium Titanates
Electroceramics
Online AccessGet full text

Cover

More Information
Summary:A core‐shell structure was observed in SrTiO3 doped with 1.2 mol% of Nb2O5, after sintering in a reducing atmosphere (5H2‐95N2) and then in an oxidizing atmosphere (air). In undoped and Al2O3‐doped SrTiO3 specimens, no core‐shell structure formed after the same sintering treatments as those for SrTiO3 doped with 1.2 mol% of Nb2O5. The measured chemical compositions of the core and shell regions of 1.2‐mol%‐Nb2O5‐doped SrTiO3 grains showed that the Sr/(Ti + Nb) ratio of the shell regions grown in air was ~1% less than that of core regions grown in 5H2‐95N2, which was in good agreement with a value predicted by available defect equations. Therefore, the observed core‐shell structure is thought to result from the formation of strontium vacancies in an oxidizing atmosphere.
Bibliography:istex:1F148A43C8614F984C3D0A4B0000092860330920
ark:/67375/WNG-NHPDBR8R-C
ArticleID:JACE3016
Supported by the Korea Science and Engineering Foundation (KOSEF) through the Center for Interface Science and Engineering of Materials (CISEM), KAIST, and also by a KOSEF‐JSPS (Japan Society for Promotion of Science) joint research program.
M. Fujimoto—contributing editor
Member, American Ceramic Society.
ISSN:0002-7820
1551-2916
DOI:10.1111/j.1151-2916.1998.tb02730.x