Creation and characterization of Fe-based High-Tc superconductors utilizing an ultraclean environment

2015 Fiscal Year Final Research Report

• Project/Area Number: 26610107
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: National Institute for Materials Science
• Principal Investigator: Uchihashi Takashi 国立研究開発法人物質・材料研究機構, 国際ナノアーキテクトニクス研究拠点, MANA研究者 (90354331)
• Co-Investigator(Renkei-kenkyūsha): YOSHIZAWA Shunsuke 物質・材料研究機構, 若手国際研究センター, ICYS研究員 (60583276)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 超伝導 / 二次元 / 原子層 / 電気伝導 / 走査トンネル顕微鏡 / 超高真空環境

Outline of Final Research Achievements

We have performed electron transport measurements on FeSe monolayers grown on SrTiO3 substrates in the ultrahigh vacuum environment. Thus far, no superconducting transition was observed for our samples. This is attributed to the fact that the conditions for preparing FeSe ultrathinfilms and/or for removing the Se protecting layer was not sufficiently good and eventually led to formation of disconnected ultrathin films. We also performed STM observation of the Si(111)-(root7xroot3)-In surface reconstruction, which exhibit superconductivity around 3 K. The STM image was observed to have a strong bias-voltage dependence together with a structural modulation with a long periodicity in the direction of [1 -1 0]. This indicated that the two atomic layer model proposed by Park-Kang was not accurate.

Free Research Field

超伝導、低温物性実験、表面科学