Low damping magnetic properties and perpendicular magnetic anisotropy in the Heusler alloy Fe1.5CoGe

Abstract

We present a study of the dynamic magnetic properties of TiN-buffered epitaxial thin films of the Heusler alloy Fe1.5CoGe. Thickness series annealed at different temperatures are prepared and the magnetic damping is measured, a lowest value of α = 2.18 × 10 −3 is obtained. The perpendicular magnetic anisotropy properties in Fe1.5CoGe/MgO are also characterized. The evolution of the interfacial perpendicular anisotropy constant K ⊥ S with the annealing temperature is shown and compared with the widely used CoFeB/MgO interface. A large volume contribution to the perpendicular anisotropy of (4.3 ± 0.5) × 10 5 J/m 3 is also found, in contrast with vanishing bulk contribution in common Co-and Fe-based Heusler alloys.

Control of Structural and Magnetic Properties of Polycrystalline Co2FeGe Films via Deposition and Annealing Temperatures

“…It is to be pointed out that T S /T a = 573 K seems to be optimal to produce Co 2 FeGe thin films with improved magnetic properties. This result is in a good agreement with previously published in [ 19 , 23 ].…”

“…Thus, FHA films are considered as attractive candidates for different multifunctional applications. It was shown in [ 5 , 17 , 19 , 22 , 23 ] that substrate temperature (T S ) and post-deposition annealing (T a ) are powerful tools to control the properties of FHA films. However, so far there is no universal law for thermal treatment conditions.…”

“…Thus, FHA with high spin polarization and moderate values of M S and A comparing to ferromagnetic metals like Fe and Co are attractive candidates for STT applications. On the other hand, a large value of α is needed to improve thermal stability in current-perpendicular-to-plane giant magnetoresistance (GMR) read sensors [17] Physical properties of FHA can be effectively tuned in a wide range by changing atomic ordering, microstructure and composition [1,2,4,[17][18][19][20][21]. Thus, FHA films are considered as attractive candidates for different multifunctional applications.…”

Novel Spin–Orbit Torque Generation at Room Temperature in an All‐Oxide Epitaxial La0.7Sr0.3MnO3/SrIrO3 System

“…The enhancement of M eff is observed for all LSMO thicknesses, confirming the universal role of SIO in enhancing the M eff of LSMO. The effective magnetization can be written as μ 0 M eff = μ 0 M s − H k,eff , [ 46 ] where H k,eff is the effective anisotropy field. This enhancement in M eff in the epitaxial LSMO/SIO is quite different from the SIO/CoFe systems, see Figure 2c, which exhibits M eff < M s , and no strong dependence on SIO thickness, as typically seen in conventional metallic systems.…”

“…This could be due to a difference in the sign of H k,eff between the epitaxial LSMO/SIO and non‐epitaxial SIO/Py, which further accentuates the peculiarity of the LSMO/SIO system. In conventional systems, H k,eff can have contributions from a bulk component (2 K u / M s ) and an interface component (2 K int / M s t LSMO ), [ 46 ] where K u and K int are the bulk and interfacial anisotropy constants, respectively. The difference between M eff and M s in the LSMO/SIO scales linearly with 1/ M s t LSMO , shown in the inset of Figure 2d, as expected from an interfacial contribution.…”