Silica and Magnesia Dopant Distributions in Alumina by High-Resolution Scanning Secondary Ion Mass Spectrometry
Trace SiO2 and MgO additive distributions in sintered alumina have been studied using high‐resolution scanning secondary ion mass spectrometry (SIMS). When doped with each additive individually, evidence is seen for both strong silicon segregation to grain boundaries (Cgb/Cgrain similar/congruent 30...
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Published in | Journal of the American Ceramic Society Vol. 82; no. 4; pp. 1001 - 1008 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Westerville, Ohio
American Ceramics Society
01.04.1999
Blackwell |
Subjects | |
Online Access | Get full text |
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Summary: | Trace SiO2 and MgO additive distributions in sintered alumina have been studied using high‐resolution scanning secondary ion mass spectrometry (SIMS). When doped with each additive individually, evidence is seen for both strong silicon segregation to grain boundaries (Cgb/Cgrain similar/congruent 300) in SiO2‐doped alumina and strong magnesium segregation to grain boundaries (Cgb/Cgrain similar/congruent 400) in MgO‐doped alumina. When codoped with both SiO2and MgO, segregation of both ions to grain boundaries is reduced by a factor of 5 or more over single doping. The additive concentrations increase proportionally in the grains, and both dopants become more uniformly distributed throughout the bulk. It is concluded that codoping with these additives increases their mutual bulk solid solubility and decreases their interfacial segregation over single doping. The beneficial effect of MgO additions in controlling microstructure development in alumina and improving corrosion resistance to aqueous HF stems from its ability to redistribute silicon ions from grain boundaries into the bulk. |
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Bibliography: | ArticleID:JACE1001 ark:/67375/WNG-NK01K5DF-7 istex:09453DADFDF7C657DC3F81FD5782071EEC7B1EA2 C. G. Pantano—contributing editor Member, American Ceramic Society. Supported by the NSF under Award No. DMR‐9625354 and through the MRSEC program under NSF Award No. DMR‐9400379. ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0002-7820 1551-2916 |
DOI: | 10.1111/j.1151-2916.1999.tb01866.x |