Papers by Author: Ryutaro Yamaki

Abstract: We have applied two kinds of experimental methods using elliptically polarized synchrotron X-rays, magnetic Compton and Bragg scattering experiments, to a single crystal of a disordered Pd_0.80Co_0.20 alloy, and have measured magnetic Compton profiles and magnetic form factors, respectively. The result of the Compton scattering experiment has shown that the electronic structure of Pd_0.80Co_0.20 is similar to that of Pd_0.72Co_0.28, and the spin moment has been evaluated. The result of the Bragg scattering experiment has reinforced that of the previous experiment [M. Ito et al.: Mater. Sci. Forum Vol. 459 (2011), p. 3.], and the spin moment estimated by the magnetic Bragg scattering has reproduced that by the magnetic Compton scattering. These results show that the joint study of the magnetic Compton and Bragg scattering provides a tool for investigating the magnetic property of alloys.

Abstract: We compare two Co/Pd multilayers with correspondingly smooth and rough interfaces. The first is a Co (1.5 nm)/Pd (2.6 nm) multilayer with a smooth interface deposited by the MBE technique, and the second is a Co (1.6 nm)/Pd (4.0 nm) multilayer with a rough interface deposited by the sputter technique. Both multilayers have almost the same perpendicular magnetic anisotropy energy, 1.15 Merg/cc for the Co (1.5 nm)/Pd (2.6 nm) multilayer and 1.20 Merg/cc for the Co (1.6 nm)/Pd (4.0 nm) multilayer, respectively. The symmetry of the wave function, which is measured using the magnetic Compton profile, is almost the same for both multilayers. This suggests that the smooth interface controls the wave function and enhances the PMA energy even if the Co/Pd multilayer has a thinner Pd layer.

Abstract: We have measured magnetic Compton profile of Co/Pd thin films sputtered on a substrate for studying the electronic structure. For the first time, a silicon nitride substrate of 100 nm thickness we used in the magnetic Compton scattering experiment. We have improved vacuum tubes of the Compton beam-line BL08W of SPring-8, and have reduced greatly the background scattering for the Compton profile. We have succeeded in measuring magnetic Compton profile of Co (0.8 nm)/Pd (1.6 nm) 400 nm multilayer.