observation of the glass-like localized state of electrons by X-ray and neutron PDF analysis

2014 Fiscal Year Final Research Report

• Project/Area Number: 24510129
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Quantum beam science
• Research Institution: Japan Atomic Energy Agency
• Principal Investigator: KODAMA Katsuaki 独立行政法人日本原子力研究開発機構, 原子力科学研究部門 量子ビーム応用研究センター, 研究主幹 (10313115)
• Co-Investigator(Renkei-kenkyūsha): SHAMOTO Shin-ichi 独立行政法人日本原子力研究開発機構, 原子力科学研究部門・量子ビーム応用研究センター, 研究主席 (90235698) ; YONEDA Yasuhiro 独立行政法人日本原子力研究開発機構, 原子力科学研究部門・量子ビーム応用研究センター, 研究主幹 (30343924)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 電荷の短距離秩序 / 中性子散乱 / PDF解析

Outline of Final Research Achievements

We have performed local structural analysis by using the atomic pair distribution function (PDF) on LiMn2O4 and YBaCo2O5 which contain the single Mn and Co sites with the half-integer valences of +3.5 and +2.5, respectively, and exhibit non-metallic conductivities. The local structure of LiMn2O4 at room temperature determined by the PDF analysis includes inequivalent Mn sites with the valences of +3 and +4, indicating that the valence electrons of Mn atom are localized at the Mn sites only with short-range correlation, resulting in the non-metallic conductivity. The similar results are obtained in YBaCo2O5. These results suggest that such a glass-like state of valence electrons may be also probable in other compounds with the transition metal ions with non-integer valences and non-metallic conductivities.

Free Research Field

固体物理