Current-induced dynamics of bubble domains in perpendicularly magnetized TbFeCo wires

Abstract

We investigated the bubble-domain dynamics in TbFeCo wires with perpendicular magnetization under electric current flows. In TbFeCo wires with relatively low saturation magnetization (M s ), the current pulse caused the bubble domains to collapse without moving. In TbFeCo wires with relatively high M s , however, the bubble domains grew in the current direction. We explain these shape changes by assessing the M s -dependent forces caused by the exchange field and magnetostatic field. We also found that we could control the current-induced behaviors of the bubble domains by using an external magnetic field.

Coherent terahertz spin-wave emission associated with ferrimagnetic domain wall dynamics

“…As RE and TM elements have different Landé-g factors [14], RE-TM ferrimagnets have two distinct temperatures; the magnetic moment compensation point T M where net magnetic moment vanishes, and the angular momentum compensation point T A where net angular momentum vanishes. For RE-TM ferrimagnets, resonance [15,16], switching [17][18][19][20][21], domain wall motion [22][23][24], and skyrmion (or bubble domain) motion [25][26][27] near these compensation points have been explored experimentally and theoretically. In particular, an experimental observation of a fast field-driven DW motion at T A in GdFeCo single-layered ferrimagnets was recently reported [23].…”

Bidirectional spin-wave-driven domain wall motion in ferrimagnets

“…As a result, previously established creation and detection schemes for ferromagnets is directly applicable to RE-TM ferrimagnets. This simple but strong benefit of RE-TM ferrimagnets have recently initiated extensive studies on ferrimagnets, which include magnetization switching [16][17][18][19], domain wall motion [20][21][22][23][24], skyrmion (or bubble domain) motion [25][26][27][28], low damping [29], and efficient spin-transfer and spin-orbit torques due to antiferromagnetic alignment of atomic spins [30,31].…”

Electric-current-induced dynamics of bubble domains in a ferrimagnetic Tb/Co multilayer wire below and above the magnetic compensation point

“…The BDs were generated in the wire as follows. 16,19 A magnetic field of more than 3 kOe was first applied perpendicular to the substrate plane upward or downward in order to align the magnetization of the wire in one direction. The center of the {Tb/Co} 7 wire was then heated for 0.5 second using a 407-nm laser of 8 mW with a magnetic field of about 1 kOe applied perpendicular to the substrate plane downward or upward.…”

“…[12][13][14] In our previous study, the electric-current-induced movements of bubble domains (BDs) in ferrimagnetic amorphous TbFeCo wires with perpendicular magnetic anisotropy with Pt cap layers were studied. 16 The effective torque which was induced by the injected spins from the Pt layers was stronger than the spin transfer torque (STT) from the electric current flowing in the TbFeCo layers. Because the BDs, whose domain walls do not reach the wire edges, are expected to be driven without the effect of the edge roughness, the current induced dynamics of BDs would allow us to distinguish the influence of such torques clearly.…”