Creation and high functionalization of La doped SrTiO3/conductive nitrides nano composites

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K14004
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 26030:Composite materials and interfaces-related
• Research Institution: Nagoya Institute of Technology (2019-2020); Kyushu University (2018)
• Principal Investigator: WATANABE KOSUKE 名古屋工業大学, 工学(系)研究科(研究院), 研究員 (40617007)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: ナノ複合体 / 酸化物 / 導電性窒化物 / 熱電変換材料 / ボトムアップ型合成

Outline of Final Research Achievements

In order to develop thermoelectric materials that can withstand high temperatures, bulk nanocomposites composed of La-doped SrTiO3 (LSTO) and TiN were synthesized and scale-up studies were carried out. The microstructure and thermoelectric properties of these sintered materials were controlled by the amount of TiN added. A clear increase in conductivity was observed with the addition of TiN, and the power factorwas improved by controlling the volume fraction of TiN compared to the LSTO single phase. On the other hand, the lattice thermal conductivity was successfully reduced by suppressing the increase in the grain size of LSTO and TiN, and the maximum value of ZT, an index of thermoelectric performance, was 0.14 (775°C).

Free Research Field

ナノ材料化学

Academic Significance and Societal Importance of the Research Achievements

酸化物中に窒化物を導入したナノ複合体の合成を、本研究で開発した方法（つまり異種酸化物被覆、窒化処理、焼結といった従来存在する方法の組み合わせ）により、容易にした。また、このようなナノ複合材料のスケールアップを実施したことによって、産業上容易に生産可能となる。さらに、異種材料間の割合やその微細組織制御によって、導電性、熱起電力、熱伝導率を制御できる可能性を示し、複合材料の新たな可能性を示した研究である。