Materials science of multi-morphism in oxides and singular structural properties

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H01733
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 26040:Structural materials and functional materials-related
• Research Institution: Nagoya University
• Principal Investigator: Harada Shunta 名古屋大学, 未来材料・システム研究所, 准教授 (30612460)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: ピコスケール / 原子構造制御 / マルチモルフィズム

Outline of Final Research Achievements

Among transition metal oxides having a plurality of valences, there is a group of substances exhibiting a multimorph, which structurally alleviates changes in the amount of oxygen and continuously changes the crystal structure depending on the composition. In this study, we focused on oxides containing periodic arrangements of surface defects called crystallographic shear structure, and established a method to control the periodic arrangement of nanoscale surface defects with picoscale accuracy by changing the amount of oxygen. .. In addition, the peculiar structural properties expressed by the nanoscale periodic structure contained in the bulk crystal were clarified. Specifically, the thermal conductivity does not change monotonically with respect to the density of surface defects and has a minimum value, which is a result of capturing the wave-like aspect of heat conduction.

Free Research Field

ピコテクノロジー

Academic Significance and Societal Importance of the Research Achievements

半導体集積回路や、低次元材料の出現など、材料の構造制御は日進月歩で微細化し続けている。このような中で、本研究ではバルク結晶中のナノスケール周期構造をピコスケールで制御できることを示唆しており、さらにそのような結晶においては、通常の材料では見られない、特異な特性を発現することが明らかとなった。今後の研究で、このような特異な特性発現を活用し、これまでの材料とは全く異なる材料、デバイスが設計されることが期待される。