Figure 6. Electric-field-induced dynamic magnetization switching.

(a) Time-dependent electric-field-induced magnetization switching in 64×64×5 (squares) and 224×224×5 nm³ (circles) Ni-free layers, corresponding to the higher remnant m_x at E=0 (see Fig. 3a). For simplicity, the piezoelectric stress is considered to be applied to the Ni film instantaneously. (b) Snapshots of the magnetization vector diagrams in 64×64×5 nm³ (top) and 224×224×5 nm³ (bottom) Ni-free layers at (from left to right) t=0.13, 0.64, 0.90 and 1.02 ns, respectively. The arrows and the dashed curves are the eye guides for the coherent magnetization rotation and domain-wall motion processes in single-domain 64×64×5 and multi-domain 224×224×5 Ni films, respectively.