IT-12-O-2156 Novel development of very high brightness and highly spin-polarized electron gun with a compact 3D spin manipulator for SPLEEM

We have already developed a novel very high brightness and high spin-polarized low energy electron microscope (SPLEEM) and applied it to clarify the magnetic property of [CoNix]y/W(110) and Au/CoNi2/W(110) during growth of ultra thin films[1-5]. Such thin multi layered films are important for current-driven domain-wall-motion devices. Our developed SPLEEM can make us the dynamic observation of the magnetic domain images possible. However the size of the spin-polarized electron gun is large and we have started to develop a new compact spin-polarized electron gun with a novel idea. In principle two devices are necessary to operate 3-dimensional spin direction; one is a spin manipulator which changes the out-of-plain spin direction and another one is a spin rotator which can change the in-plain spin direction. We have proposed a multi-pole Wien filter which enables 3-dimensional spin operation with one device. The developed 3D multi-pole spin manipulator which has 8 poles in the present development and the magnetic and electric field in the multi-poles Wien filter as shown in Fig.1. Uniform field can be obtained at the center part of the Wien filter with 8 poles and 12 poles, however 4 poles filter gives non-uniform field even at the center. In the present development 8 poles Wien filter has been adopted. The results of magnetic images and asymmetries of Co(4ML)/W(110) vs. polar and azimuthal angles are shown in Fig.2. The results clearly show that spin direction can be operated three dimensionally with one device.
1)  X.G. Jin et al., Appl. Phys. Express 1, 045002 (2008).
2)  N. Yamamoto et al., J. Appl. Phys.103, 064905 (2008).
3)  M.Suzuki et al., Appl. Phys.Express 3, 026601 (2010).
4)  M.Suzuki et. al., J.Phys. Cond. Matt. 25, 406001-1-8 (2013) (Short News on IOP web and IOP select).
5)  K. Kudo et al., J.Phys. Cond.Matte. 25, 395005-1-6 (2013).