Identification of ultradilute dopants in ceramics

Isao Tanaka*, Teruyasu Mizoguchi, Masafumi Matsui, Satoru Yoshioka, Hirohiko Adachi, Tomoyuki Yamamoto, Toshihiro Okajima, Masanori Umesaki, Wai Yim Ching, Yoshiyuki Inoue, Masataka Mizuno, Hideki Araki, Yasuharu Shirai

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

81 Citations (Scopus)


The properties of ceramic materials are strongly influenced by the presence of ultradilute impurities (dopants). Near-edge X-ray absorption fine structure (NEXAFS) measurements using third-generation synchotron sources can be used to identify ultradilute dopants, provided that a good theoretical tool is available to interpret the spectra. Here, we use NEXAFS analysis and first-principles calculations to study the local environments of Ga dopants at levels of 10 p.p.m in otherwise high-purity MgO. This analysis suggests that the extra charge associated with substitutional Ga on a Mg site is compensated by the formation of a Mg vacancy. This defect model is then confirmed by positron lifetime measurements and planewave pseudopotential calculations. This powerful combination of techniques should provide a general method of identifying the defect states of ultradilute dopants in ceramics.

Original languageEnglish
Pages (from-to)541-545
Number of pages5
JournalNature Materials
Issue number8
Publication statusPublished - 2003 Aug
Externally publishedYes

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


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