Spin–Orbit Torque Switching of a High-Quality Perpendicularly Magnetized Ferrimagnetic Heusler Mn₃Ge Film

Abstract

Current-induced spin−orbit torque (SOT) switching of magnetization has attracted great interest due to its potential application in magnetic memory devices, which offer low-energy consumption and high-speed writing. However, most of the SOT studies on perpendicularly magnetized anisotropy (PMA) magnets have been limited to heterostructures with interfacial PMA and poor thermal stability. Here, we experimentally demonstrate a SOT magnetization switching for a ferrimagnetic D0 22 -Mn 3 Ge film with high bulk PMA and robust thermal stability factor under a critical current density of 6.6 × 10 11 A m −2 through the spin Hall effect of an adjacent capping Pt and a buffer Cr layer. A large effective damping-like SOT efficiency of 2.37 mT/10 10 A m −2 is determined using harmonic measurements in the structure. The effect of the double-spin source layers and the negative-exchange interaction of the ferrimagnet may explain the large SOT efficiency and the manifested magnetization switching of Mn 3 Ge. Our findings demonstrate that D0 22 -Mn 3 Ge is a promising candidate for application in high-density SOT magnetic random-access memory devices.

Thickness Dependence of Interface‐Generated Spin Currents in Ferromagnet/Ti/CoFeB Trilayers

“…To examine the interface-generated spin currents and associated SOTs in the FM/Ti/CoFeB trilayer, we perform current-induced magnetization switching measurement with and without an external magnetic field B x along the current direction. [14][15][16][51][52][53][54][55][56][57][58] It is noted that both in-plane and out-of-plane SOTs caused by the SOF and SOP spin currents, respectively, always contribute to the current-induced magnetization switching regardless of the application of B x . However, in the presence of B x , in-plane SOT dominates the current-induced magnetization switching since the magnitude of in-plane SOT is larger than that of outof-plane SOT in the magnetic trilayers.…”

Giant Spin–Orbit Torque in Antiferromagnetic-Coupled Pt/[Co/Gd]N Multilayers with Suppressed Spin Dephasing and Robust Thermal Stability

“…This is attributed to the changeable compensation of Co and Gd magnetic moments with N; the minimum magnetization appears near t c . The μ 0 H k of Pt/Co(1) is 0.90 T. Next, the thermal stability factor (Δ T ) was quantified using a cylinder with 28 nm diameter for typical MRAM nodes by eq , Δ T = K eff V magnet / k B T where K eff = μ 0 H k M S 2 and V magnet are the effective perpendicular magnetic anisotropy energy density and cylinder volume of magnets. Figure d shows that Δ T of Pt/[Co/Gd] N exhibits bulk-like characteristics, increasing from 41.0 ( N = 6) to 82.3 ( N = 10), which benefits from the increase of t [Co/Gd] and meets the standard of 60.0 for application .…”

Unraveling the Magnetic Ground State and Local Lattice Distortions in Z2XY-Type Full Heusler Compounds: An EXAFS Study

“…Magnetic Heusler compounds are one of the most fascinating classes of magnetic materials not only from an application-oriented standpoint − but also for their outstanding fundamental properties. − The large varieties of physical properties emerge because of the adaptable structure of the Heusler system, which offers excellent chemical flexibility. Traditionally, in X 2 YZ Heusler, the X and Y atoms are transition metals (d and f) and Z is a main group element (sp) forming an L2 1 structure.…”