Vortex states on a compositinal graded superconductor treated under a mega gravity process

Okayasu, Satoru  ; Ono, Masao  ; Nishio, Taichiro*; Nakai, Noriyuki; Hayashi, Nobuhiko*; Machida, Masahiko  ; Iguchi, Yusuke*; Mashimo, Tsutomu*

In high gravitational fields up to one million G, sedimentation of cecompositional atoms may occur even in solid. An In-Pb alloy sample (In:Pb=8:2) was prepared under a mega-gravity (1.02 MG) circumstance at 125C for 100 hours. After the maga-gravity treatment, an atomic scaled compositionally graded structure is formed in entire sample. A sample with continuously varying superconducting transition temperatures Tc is obtained. The effect of the varying Tc on vortices is investigated using a scanning SQUID microscope.