Exploration and Applied Engineering of Novel Functions Based on Nanostructures in Transparent Oxides

Hideo Hosono (Professor, Tokyo Institute of Technology)

Discovery of new functions hidden in unexplored materials
Creation of new types of high-temperature superconductor
LaFeAsO (Iron-oxypnictide) Transition temperature = 32K (11% of O replaced by F)

Research Overview
New functional materials that outstrip conventional concepts and physical properties are sought by testing various combinations encompassing constituent elements of oxides and related compounds. It has been discovered that materials containing magnetic elements exhibit superconductivity at high temperatures. This search for a new superconductor family has received global attention.

Impact of Research Achievements
■ It has been discovered that LaFeAsO (an oxypnictide compound) whose oxygen atoms are partially replaced with fluorine atoms becomes a high-temperature superconductor with a maximum transition temperature of 32K. (Thesis published by the American Chemical Society.)
This is a third-category high-temperature superconductor (a compound containing Fe), and is different from common metallic materials and cuprate materials.
■ No other compounds containing Fe have been confirmed to exhibit such high transition temperatures, and this discovery is believed to be a new type of high-temperature superconductor.
■ Size of global superconductive industry market will be 2-3 trillion yen in 2020.
■ Triggered by this discovery, Fe-based superconductors with higher transition temperature and with different crystal structures have been found. The researches have been performed extensively all over the world.
  i) One of "Breakthrough of the Year 2008" selected by the journal Science
  ii) The most cited science topic in 2008 (249th report: By Thomson Reuters)