Local atomic and electronic structure analysis by STEM-EELS/EDX for thermoelectric materials

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K14108
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Physical properties of metals/Metal-base materials
• Research Institution: Nagoya University
• Principal Investigator: TATSUMI KAZUYOSHI 名古屋大学, 未来材料・システム研究所, 准教授 (00372532)
• Co-Investigator(Renkei-kenkyūsha): MUTO Shunsuke 名古屋大学, 未来材料システム研究所, 教授 (20209985)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 電子チャネリング / EELS / EDX / 透過電子顕微鏡 / 第一原理計算

Outline of Final Research Achievements

We investigated site-by-site local atomic and electronic structures by utilizing the electron channeling effects on TEM-EELS/EDX with the incident beam direction scanned systematically.
The occupancies of Co at the Fe sites in a ferrite were quantified. The preferable sites were consistent with the fist-principles estimation according to the formation energies of Co among the Fe sites. Also, the transition metal occupations and the valence states in a Li-ion battery anode material were analyzed.
Moreover in order to improve the theoretical treatment of the phonon effects on the quantitative analyses, we initiated to calculate the phonon states using the force constants obtained by first principles calculations. As its by-product, we investigated microscopic mechanisms of lattice thermal conductivities among silicon nitride polymorphs.

Free Research Field

ナノ材料科学