[22a-W241-1~11] CS.6 10.1/10.2/10.3 Code sharing session "Emerging control-methods of magnetization and related phenomena"

▼ [22a-W241-1] Electric-field effect on domain structure in MgO/CoFeB/Ta

〇Takaaki Dohi¹, Shun Kanai^1,2, Atsushi Okada¹, Shunsuke Fukami^2,3, Fumihiro Matsukura^4,1,2, Hideo Ohno^1,2,3,4 (1.Laboratory for Nanoelectronics and Spintronics, RIEC, Tohoku Univ., 2.CSIS, Tohoku Univ., 3.CIES, Tohoku Univ., 4.WPI-AIMR, Tohoku Univ.)

Keywords:CoFeB/MgO,electric-field effect,domain structure

We investigate the electric-field effects on the domain structures in MgO/CoFeB/Ta, whose magnetic parameters, such as magnetic anisotropy and damping constant, can be modulated by the application of an electric field. Domain structures are observed at demagnetized state under several electric fields E by a magneto-optical Kerr effect microscope. The observed maze domain structures are analyzed by two-dimensional fast Fourier transform, which shows the domain patterns possess an isotropic characteristic period (domain width). The domain width is determined to be 1.75 μm at E = 0, which increases to 2.00 μm at E = +0.11 V/nm. The comparison of the obtained domain width and calculated ones suggests that exchange stiffness constant of 10.4 pJ/m at E = 0 is modulated by plus/minus a few percent by the application of E = ±0.11 V/nm.