80th Magnetic Materials Center Seminar
July 9, 2008, 9:00-
7th floor small seminar room, Sengen
Spin polarization results of Co2MnGa0.5Sn0.5
B. Varaprasad
Highly spin polarized materials with high Curie temperatures (Tc) are strongly desired for future spintronics device applications. Though there were theoretical predictions of several Heusler alloys with 100% spin polarization (P), such high polarization has not been confirmed so far at room temperature. From the DOS calculations by Galanakis et al., even though the Fermi levels of these two alloys lie on the same side of the band gap, the density of the spin-up states is higher in Co2MnGa than in Co2MnSn system near the Fermi level and both these Heusler alloys have high Tc. From previous point contact Andreev reflection (PCAR) experiments Co2MnSn has been shown to possess 63 and 65% with quaternary element additions. Hence the quaternary Co2MnGa0.5Sn0.5 system was chosen for the spin polarization study. I will present the structural, magnetic and spin polarization results.


T. Furubayashi


Nano-structured materials design with phase separation
B. J. Park
To understand the phase separation mechanism can give an opportunity to design the nano-structured materials. The reaction of phase separation is consisted with the spinodal decomposition and the nucleation and growth reaction. An interconnected structure could be formed by the spinodal decomposition and the nucleation and growth reaction could give a droplet structure. Furthermore, with adjusting the cooling rate, the size of separated phase could be controlled. In this presentation, the phase separation in metallic glasses, my Ph.D. thesis, will be briefly introduced. And the critical composition of Fe-Cu binary alloy that could have the interconnected structure will be suggested to make a metal leaf with pore.