11:15 〜 11:30
▼ [11a-S302-9] Current Driven Domain Wall Motion in Compensated Ferrimagnets: Fast Domain Wall Velocity in a Wide Temperature Range Without External Magnetic Field
キーワード：Nanowires, Racetrack memory, Ferrimagnetic
Spintronics applications are being extensively followed for high-performance logic computing technologies and racetrack memories[1]. The principal difficulties are to reach small bits, high thermal stability, and track them at high speed. Although there is a report that the domain wall moving speed is improved by using the angular momentum compensation of RE-TM[2], as regards stable driving over a wide temperature range has not been achieved. In this work, we designed Gdx(Fe88Co22)100-x magnetic wires to achieves great domain wall motion over a wide temperature range.
Subsequently, we measured the domain wall velocity. We applied a single voltage pulse and then observed the DW motion by using a Kerr microscope. The velocity of the domain wall was determined by dividing the change in the position of the domain wall by the duration of the current pulse. Figure 1(a) shows our measurement results in the Pt (5)/ Gd24 (Fe88Co22)76 (20)/SiN (10) sample as a function of current density. As a result, without applying an in-plane external magnetic field, the fastest DW velocity of 2000 m/s has been obtained as far as we know in the reports. Figure 1(b) shows the DW velocity of the Gd24(Fe88Co12)76 as a function of operating temperature. DW speed obtained stable between the temperature range of R.T. <Top<70°C for Gd24FeCo76 when pulse current of 30nsec and 3nsec is injected into the wire.
As a result, a wide temperature range with a DW velocity of 1500 m/s has been obtained in Gd24(Fe88Co12)76 for a short pulse current which is more stable in comparison with the previous reports.
Subsequently, we measured the domain wall velocity. We applied a single voltage pulse and then observed the DW motion by using a Kerr microscope. The velocity of the domain wall was determined by dividing the change in the position of the domain wall by the duration of the current pulse. Figure 1(a) shows our measurement results in the Pt (5)/ Gd24 (Fe88Co22)76 (20)/SiN (10) sample as a function of current density. As a result, without applying an in-plane external magnetic field, the fastest DW velocity of 2000 m/s has been obtained as far as we know in the reports. Figure 1(b) shows the DW velocity of the Gd24(Fe88Co12)76 as a function of operating temperature. DW speed obtained stable between the temperature range of R.T. <Top<70°C for Gd24FeCo76 when pulse current of 30nsec and 3nsec is injected into the wire.
As a result, a wide temperature range with a DW velocity of 1500 m/s has been obtained in Gd24(Fe88Co12)76 for a short pulse current which is more stable in comparison with the previous reports.