Large voltage-induced magnetic anisotropy change in a few atomic layers of iron.
In the field of spintronics, researchers have manipulated magnetization using spin-polarized currents. Another option is to use a voltage-induced symmetry change in a ferromagnetic material to cause changes in magnetization or in magnetic anisotropy. However, a significant improvement in efficiency is needed before this approach can be used in memory devices with ultralow power consumption. Here, we show that a relatively small electric field (less than 100 mV nm(-1)) can cause a large change (approximately 40%) in the magnetic anisotropy of a bcc Fe(001)/MgO(001) junction. The effect is tentatively attributed to the change in the relative occupation of 3d orbitals of Fe atoms adjacent to the MgO barrier. Simulations confirm that voltage-controlled magnetization switching in magnetic tunnel junctions is possible using the anisotropy change demonstrated here, which could be of use in the development of low-power logic devices and non-volatile memory cells.
Maruyama
T
T
Graduate School of Engineering Science, Osaka University, Toyonaka, Japan.
Shiota
Y
Y
Nozaki
T
T
Ohta
K
K
Toda
N
N
Mizuguchi
M
M
Tulapurkar
A A
AA
Shinjo
T
T
Shiraishi
M
M
Mizukami
S
S
Ando
Y
Y
Suzuki
Y
Y