Effects of Crystalline Disorder on Interfacial and Magnetic Properties of Sputtered Topological Insulator/Ferromagnet Heterostructures

Abstract

Thin films of Topological insulators (TIs) coupled with ferromagnets (FMs) are excellent candidates for energy-efficient spintronics devices. Here, the effect of crystalline structural disorder of TI on interfacial and magnetic properties of sputter-deposited TI/FM, Bi2Te3/Ni80Fe20, heterostructures is reported. Ni and a smaller amount of Fe from Py was found to diffuse across the interface and react with Bi2Te3. For highly crystalline c-axis oriented Bi2Te3 films, a giant enhancement in Gilbert damping is observed, accompanied by an effective out-of-plane magnetic anisotropy and enhanced damping-like spin-orbit torque (DL-SOT), possibly due to the topological surface states (TSS) of Bi2Te3. Furthermore, a spontaneous exchange bias is observed in hysteresis loop measurements at low temperatures. This is because of an antiferromagnetic topological interfacial layer formed by reaction of the diffused Ni with Bi2Te3 which couples with the FM, Ni80Fe20. For increasing disorder of Bi2Te3, a significant weakening of exchange interaction in the AFM interfacial layer is found. These experimental results Abstract length is one paragraph.

References in corpus (9)

• Quantized Anomalous Hall Effect in Magnetic Topological Insulators
• High-precision realization of robust quantum anomalous Hall state in a hard ferromagnetic topological insulator
• Control of spin-orbit torques by interface engineering in topological insulator heterostructures
• Tunable interlayer magnetism and band topology in van der Waals heterostructures of MnBi2Te4-family materials
• Changes of Magnetism in a Magnetic Insulator due to Proximity to a Topological Insulator
• Incipient antiferromagnetism in the Eu-doped topological insulator Bi${}_2$Te${}_3$
• Strongly Enhanced Gilbert Damping in 3d Transition Metal Ferromagnet Monolayers in Contact with Topological Insulator Bi2Se3
• Antiferromagnetic VdW Phase at the Interface of Sputtered Topological Insulator/Ferromagnet-Bi2Te3/Ni80Fe20 Heterostructures
• Voltage-control of damping constant in magnetic-insulator/topological-insulator bilayers

Cited by in corpus (1)

• Spin-orbit torques from topological insulator surface states: Effect of extrinsic spin-orbit scattering on an out-of-plane magnetization