Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Okayasu, Satoru; Ono, Masao; Nishio, Taichiro*; Iguchi, Yusuke*; Mashimo, Tsutomu*
Defect and Diffusion Forum, 323-325, p.545 - 548, 2012/04
Times Cited Count:0 Percentile:0.01Atomic sedimentation in solid occurs under mega-gravity treatment. As the result, partially melt-growth in -phase of BiPb-alloy occurs. Small difference of densities between fully hcp structure of BiPb and that of partially defected BiPb are enhanced under mega-gravity, and cause the separation of the -phase. Superconducting properties differs between the separated two phases.
Osawa, Takahito; Ono, Masao; Esaka, Fumitaka; Okayasu, Satoru; Iguchi, Yusuke*; Hao, T.; Magara, Masaaki; Mashimo, Tsutomu
EPL; A Letters Journal Exploring the Frontiers of Physics, 85(6), p.64001_1 - 64001_5, 2009/03
Times Cited Count:6 Percentile:41.75(Physics, Multidisciplinary)Pure tin metals were centrifuged at 1 and at 220 C for 100 hours, 0.40 at 220-230 C for 24 hours, and 0.25 at 220 C for 24 hours. Their isotopic compositions were measured by a secondary ion mass spectrometer (SIMS). Sn/Sn and Sn/Sn ratios of the 1.02 sample were considerably different than the initial compositions, and the magnitude of isotopic fractionation reached 2.6%. A three-isotope diagram of Sn/Sn versus Sn/Sn shows conclusively that isotopic fractionation caused by a gravitational field depended only on isotopic mass.
Okayasu, Satoru; Ono, Masao; Nishio, Taichiro*; Iguchi, Yusuke*; Mashimo, Tsutomu
no journal, ,
no abstracts in English
Okayasu, Satoru; Ono, Masao; Nishio, Taichiro*; Iguchi, Yusuke*; Mashimo, Tsutomu
no journal, ,
Sedimentation of atoms can be caused under mega-gravity field even in solid. A composition-graded structure can be formed with the preparation in multi-component condensed matter. In this study, we performed a mega-gravity preparation (110 G, 130C, 100h) on a thin plate sample (0.7mm in thickness) of intermetallic superconducting compound BiPb. After the preparation, a visible four-layered structure appeared indicating different microscopic structures. In the mid two layers, the composition-graded structures were achieved. To investigate the superconducting states of each layer, direct vortex observations are accomplished for each layer with a scanning SQUID microscope. No vortex can be observed in the one of the composition-graded layer at higher gravity region. On the other hand, vortices can penetrate into other three layers. Each layer shows different superconducting property. We discuss the differences of the vortex states at the individual layers.
Okayasu, Satoru; Iguchi, Yusuke*; Ono, Masao; Nishio, Taichiro*; Mashimo, Tsutomu
no journal, ,
A homogeneous Bi-Pb alloy was treated under mega-gravity field. Sedimentation and associated crystallization occurred during the process. The compositional graded superconducting alloy is obtained. The superconductivity parallel to gravity is Pb, and perpendicular to gravity is BiPb.
Okayasu, Satoru; Ono, Masao; Nishio, Taichiro*; Nakai, Noriyuki; Hayashi, Nobuhiko*; Machida, Masahiko; Iguchi, Yusuke*; Mashimo, Tsutomu*
no journal, ,
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.