講演情報
[23p-1BJ-11]Significant Current-Induced Domain Wall Motion Improvement in Laser-Annealed GdFeCo and GdFe Nanowires
〇(P)Mojtaba Mohammadi1, Satoshi Sumi1, Kenji Tanabe1, Hiroyuki Awano1 (1.Memory Engineering Laboratory, Toyota Technological Institute, Nagoya 468-8511, Japan)
キーワード：
Racetrack Memory (RM)、Laser-Annealing (LA)、Current-Induced Domain Wall Motion (CIDWM)
One of the obstacles in advancing racetrack memory (RM) technology lies in achieving stable and high velocities for domain walls (DWs) while concurrently keeping power consumption at a minimum. Recent investigations into ferrimagnetic nanowires have disclosed a correlation between the DW shape and DW velocity within nanowires [1]. Noteworthy studies have delved into the impact of edge pinning on sub-micron wires, emphasizing its role in influencing DW dynamics [2]. Researchers have effectively employed thermal annealing and ion beam irradiation as strategic measures to overcome disorders and enhance DW dynamics [3,4]. Our study introduces an innovative laser-annealing (LA) process designed to modify wire edges, reducing the pinning effect and facilitating a smoother DW movement along the nanowire. To achieve this, film stacks of Pt(5nm)/Gd27(FeCo)73(20nm)/SiN(10nm) and Pt(5nm)/Gd27Fe73(20nm)/SiN(10nm) with similar concentration of 27 atomic% for Gd content, were deposited using magnetron sputtering. Current-induced domain wall motion (CIDWM) measurements indicate a significant enhancement in DW motion velocity for both GdFeCo and GdFe samples following the LA process. The Velocity of the DW vs. current density after applying a 3 ns pulse duration to both GdFeCo and GdFe samples is shown in Figure 1(a) and 1(b), respectively. At a current density of 4.3×1011 A/m2 (5.2×1011 A/m2), the DW velocity exhibited a remarkable enhancement for GdFeCo (GdFe), soaring from approximately 760 m/s (770 m/s) to 1470 m/s (1430 m/s). Beyond this point, the motion of the DW remains constant in the laser-annealed condition over a wide range of applied currents.