This review shows the highlights of a 4-year-long research project supported by the
Japanese Government to explore new superconducting materials and relevant functional …

Fe-based superconductors have attracted research interest because of their rich structural
variety, which is due to their layered crystal structures. Here we report the new-structure-type …

Elucidating the nature of the magnetic ground state of iron-based superconductors is of
paramount importance in unveiling the mechanism behind their high-temperature …

Study of superconductivity in layered iron-based materials was initiated in 2006 by Hosono's
group, and boosted in 2008 by the superconducting transition temperature, Tc, of 26 K in …

We report the fabrication of small (Ba, A) Fe 2 As 2 (A: Na, K) coils using 10 m-class long
round wires, fabricated by the powder-in-tube method. Coils are sintered using the hot …

We report the fabrication and systematic characterizations of multi-filament (Ba, A) Fe 2 As 2
(A: Na, K) round wires processed under high pressure. The evaluated transport and …

We report the results of a systematic investigation of the phase diagram of the iron-based
superconductor system, Ba 1− x Na x Fe 2 As 2, from x= 0.1 to x= 1.0 using high-resolution …

Abstract We fabricated (Ba, Na) Fe 2 As 2 superconducting wires using the powder-in-tube
method and hot isostatic pressing. By improving powder synthesis processes compared with …

The recently discovered C 4 tetragonal magnetic phase in hole-doped members of the iron-
based superconductors provides insights into the origin of unconventional …

(La0. 5–x Na0. 5+ x) Fe2As2 ((La, Na) 122) is an interesting system in the sense that either
electrons (x< 0) or holes (x> 0) can be doped into the Fe2As2 layers, simply by changing the …