Local structure of amorphous EuO-TiO 2thin films probed by x-ray absorption fine structure

Yanhua Zong, Koji Fujita, Hirofumi Akamatsu, Seisuke Nakashima, Shunsuke Murai, Katsuhisa Tanaka

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

We have investigated the local structure of amorphous oxides in EuO-TiO 2system to understand the mechanism that gives rise to curious ferromagnetic properties recently observed in the system. X-ray absorption spectroscopy has been performed on amorphous EuTiO 3and Eu 2TiO 4thin films prepared by the pulsed-laser-deposition method. The Ti K-edge X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) data analyses reveal that the coordination number of Ti 4+ in the amorphous thin films is around 4, which is in sharp contrast to their crystalline counterparts, where Ti 4+ ions are octahedrally coordinated by oxide ions. It is therefore inferred that Ti 4+ acts as a network-forming cation in the random network structure of the amorphous oxides. From the Eu L 3-edge EXAFS data analyses, it is found that the coordination number of Eu 2+ is much lower and the nearest Eu-O bond length is shorter in the amorphous thin films than in the crystalline counterparts. The amorphization-induced enhancement of ferromagnetic interactions observed in the EuO-TiO 2system is discussed in terms of the local environment around Eu 2+ ions.

Original languageEnglish
Pages (from-to)716-720
Number of pages5
JournalJournal of the American Ceramic Society
Volume95
Issue number2
DOIs
Publication statusPublished - Feb 1 2012
Externally publishedYes

Fingerprint

X ray absorption
Oxides
Amorphous films
Ions
X rays
Crystalline materials
Thin films
X ray absorption spectroscopy
Amorphization
Bond length
Pulsed laser deposition
Cations
Positive ions

All Science Journal Classification (ASJC) codes

  • Ceramics and Composites
  • Materials Chemistry

Cite this

Local structure of amorphous EuO-TiO 2thin films probed by x-ray absorption fine structure. / Zong, Yanhua; Fujita, Koji; Akamatsu, Hirofumi; Nakashima, Seisuke; Murai, Shunsuke; Tanaka, Katsuhisa.

In: Journal of the American Ceramic Society, Vol. 95, No. 2, 01.02.2012, p. 716-720.

Research output: Contribution to journalArticle

Zong, Yanhua ; Fujita, Koji ; Akamatsu, Hirofumi ; Nakashima, Seisuke ; Murai, Shunsuke ; Tanaka, Katsuhisa. / Local structure of amorphous EuO-TiO 2thin films probed by x-ray absorption fine structure. In: Journal of the American Ceramic Society. 2012 ; Vol. 95, No. 2. pp. 716-720.
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