Thermal switching effect by electrical currents

2015 Fiscal Year Final Research Report

• Project/Area Number: 26610099
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: Tokyo University of Science (2015); Nagoya University (2014)
• Principal Investigator: Okazaki Ryuji 東京理科大学, 理工学部, 講師 (50599602)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 熱拡散率 / 熱伝導率 / ゼーベック係数 / コバルト酸化物

Outline of Final Research Achievements

In this research project, we have developed a thermal diffusivity measurement system by utilizing a non-contact thermometer, which allows us to measure the sample temperature even in a large current density. This technique can be used to evaluate the thermal conductivity measurements under currents. Furthermore, we have grown the cobalt oxide Ca3Co4O9 single crystal samples for this measurement. We also substitute Rh for Co sites to investigate the electronic state of this material. In Rh-substituted samples, the resistivity and the Seebeck coefficient are systematically varied, and finally the power factor is significantly increased. As a future study, the thermal diffusivity and thermal conductivity should be measured in these materials.

Free Research Field

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