Effect of mechanical stress on defect equilibrium of nonstoichiometric oxides

• Project/Area Number: 24656375
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Single-year Grants
• Research Field: Inorganic materials/Physical properties
• Research Institution: Tohoku University
• Principal Investigator: KAWADA Tatsuya 東北大学, 環境科学研究科, 教授 (10271983)
• Project Period (FY): 2012-04-01 – 2014-03-31
• Project Status: Completed (Fiscal Year 2013)
• Budget Amount: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2013: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2012: ¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000)
• Keywords: 酸素不定比性 / 応力 / 欠陥平衡 / 酸素センサ / ペロブスカイト型酸化物 / 不定比性酸化物 / 酸素空孔 / 格子間酸素 / 起電力 / 酸素ポテンシャル

Research Abstract

This research aimed at experimental quantification of the effect of mechanical stress on the defect equilibrium of oxide materials, (La,Sr)CoO3, (La,Sr)(Co,Fe)O3, (La,Sr)FeO3, La2NiO4, nd LaMnO3 were selected as the model materials. A YSZ ball was indented onto the sample surfaces and the potential between the electrodes placed on YSZ and on the sample were measured as a function of time. With the materials with oxygen deficient nonstoichiometry, the potential showed sudden decrease upon loading, and increased upon its release. During the load was kept constant, the potential decayed to the original value with a time constant equivalent to that of oxygen vacancy diffusion. The effect of the stress on the chemical potential was quantified from the emf shift. It was consistent with the thermodynamic calculation based on the chemical expansion coefficient of the corresponding materials.

Research Products

• [Journal Article] Transient shift of local oxygen potential in nonstoichiometric oxides upon application of mechanical stress (2014)
  • Author(s): Tatsuya Kawada, Tomohisa Masumitsu. Yuta Kimura, Satoshi Watanabe, Shin-ichi Hashimoto, Keiji Yashiro, Koji Amezawa
  • Journal Title: J. Electroceramics Volume: 32 Issue: 1 Pages: 78-85
  • DOI: 10.1007/s10832-013-9885-x
  • Peer Reviewed
• [Presentation] 機械的応力による金属酸化物の電気化学特性への影響 (2013)
  • Author(s): 五井友基, 八代圭司, 渡辺智, 川田達也, 橋本真一
  • Organizer: 第39回固体イオニクス討論会
  • Place of Presentation: 熊本
• [Presentation] Experimental Evaluation of Oxygen Nonstoichiometry under a Mechanical Stress (2013)
  • Author(s): Tatsuya Kawada, Yuki Gonoi, Yuta Kimura, Tomohisa Masumitsu, Keiji Yashiro, Shin-ichi Hashimoto, Koji Amezawa
  • Organizer: MS&T2013
  • Place of Presentation: Montreal, Quebec, Canada
• [Presentation] Experimental Evaluation of Oxygen Nonstoichiometry under a Mechanical Stress (2013)
  • Author(s): Tatsuya Kawada, Yuki Gonoi, Yuta Kimura, Tomohisa Masumitsu, Keiji Yashiro, Shin-ichi Hashimoto
  • Organizer: MS&T'13 (Materials Science and Technology 2013)
  • Place of Presentation: Montreal, Quebec, Canada
  • Invited
• [Presentation] Influence of mechanical stress on oxygen potential in nonstoichiometric oxides (2012)
  • Author(s): T. Masumitsu, S. Watanabe, S. Hashimoto, K. Amezawa, T. Kawada
  • Organizer: ECI Conference Series, Nonstoichiometric Coumpunds-V
  • Place of Presentation: Taormina, Sicily, Italy
• [Presentation] Influence of Mechanical Stress on Oxygen Potential in Nonstoichiometric Oxides (2012)
  • Author(s): Tomohisa Masumitsu, Satoshi Watanabe, Shin-ichi Hashimoto, Koji. Amezawa, and Tatsuya Kawada
  • Organizer: ECI Conference Series "Nonstoichiometric Compounds V"
  • Place of Presentation: Sicily, Italy
• [Presentation] Compositional and Mechanical Stabilities of a (La,Sr)(Co,Fe)O3-δ Cathode under SOFC Operation (2012)
  • Author(s): Tatsuya Kawada, Mi Young Oh, Hidetaka Watanabe, Yuta Kimura, Yoshinobu Fujimaki, Tomohisa Masumitsu, Satoshi Watanabe, Shin-ichi Hashimoto, and Koji Amezawa
  • Organizer: "Ionic and Mixed Conducting Ceramics 8" in 221st Electrochemical Society Meeting
  • Place of Presentation: Seattle, WA, USA
  • Invited