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Research

We develops and evaluates materials, focusing on "superconducting materials," "lithium secondary battery materials," and "semiconductor materials for radiation detector," as functional materials that can utilize the functions of electrons and ions in materials.

#1 Superconductor

Superconductors features such as zero electrical resistance at temperatures below the critical temperature. In our laboratory, we are particularly focusing on copper oxide conductors (HTCS), which are members of a class of materials that share a CuO2 surface that is responsible for superconductivity. Although about 35 years have passed since their discovery, elucidation of the mechanism of superconductivity is still one of the most important issues in physics.
Among copper oxide superconductors, we are focusing on multilayer superconductors with three or more CuO2 planes in the unit lattice. Previous studies have shown that the inner CuO2 planes of multilayered superconductors are ideally clean, revealing the essential electronic state of HTCS, which has been difficult to see until now.

#2 Lithium Secondary Battery

Lithium secondary batteries are rechargeable and reusable batteries with high energy density, and their applications are expanding from mobile devices to larger devices. One of the keys to battery performance is the cathode material. We are searching for new materials with high capacity, high energy density, and high safety by using high temperature and high pressure technology. We have successfully prepared CaFe2O4-type LiMn2O4 and Marinite-type Li3M(PO4)2 (M = V, Cr, Fe), etc. CaFe2O4-type LiMn2O4 and Li3M(PO4)2 have shown relatively good electrochemical properties as positive electrode materials.

#3 Semiconductor for Radiation Detector

Gamma rays and X-rays are used in diverse fields such as astrophysics, medical care, and nondestructive testing. In order to measure radiation accurately, the development of highly reliable semiconductor materials is required. In our laboratory, we are focusing on TlBr and synthesizing single crystal samples.TlBr is composed of elements with large atomic numbers (Tl : 81, Br : 35) and has a band gap of 2.68 eV, making it a promising material for room temperature operation. We are working to produce high-quality crystals by optimizing the composition and "Liquinert" techniques.

Contacts

〒125-8585
6-3-1, Niijuku, Katsushika, Tokyo, Japan
Research bldg. 10F Tokiwa Lab

■Our lab is located 8-minute walk from Kanamachi Station on the JR Joban Line (Local service, direct connection to the Tokyo Metro Chiyoda Line) or Keisei Kanamachi Station on the Keisei Kanamachi Line.