54th Magnetic Materials Center Seminar
August 10, 2007, 9:00
7th floor seminar room, Sengen
optimization of sputtering conditions for (001) oriented MgO on SiO2
B. Varaprasad
Magnetic tunnel junctions have attracted much attention due to its potential applications in spintronic devices. Large MR ratio is required for device applications. To get large TMR growing (001) oriented MgO is vital part. So I would like discuss my work on preparing the (001) oriented MgO on SiO2 substrate.

Spin polarization (P) dependence on lattice vector (k).
RajaniKanth
Spin dependent coherent tunneling in (bcc) Fe/MgO/Fe or Co/MgO/Co sandwiches is a well known phenomenon. In order to obtain the coherent state at the Fe or Co/ MgO interface, the orientation of Fe or Co and MgO in (001) direction is a necessary condition. Recently it has been found that the (bcc) FeCo/MgO/FeCo can also give rise to large MR due to spin dependent coherent tunneling. In order to understand the clear dependence of MR on different orientations of ferromagnetic layers, density of states in different orientations has to be studied. Measuring the spin polarization (P) of different films grown in various orientations can reveal the spin polarization (P) dependence on lattice vector (k). In this aspect, I will present our preliminary results of spin polarization of FeCo(100) films, and compare with the spin polarization of polycrystalline Fe and Co films measured with PCAR. This work is being carried with the collaboration of Prof Sahashi at Tohoku University.

CIPGMR of Co2FeAl0.5Si0.5 based multi layered films
T. Furubayashi
In this seminar, I would like to report the results of the recent experimets on CIPGMR of multi layered films containing Co2FeAl0.5Si0.5 (CFAS) Heusler alloy. The topics are as follows.
1) Effects of in situ annealing of CFAS on CIPGMR of CFAS/Cu/CoFe spin valves
2) Synthetic antiferromagnetic structure with CFAS: magnetization and CIPGMR