Spin‐Charge Conversion in Fe/Au/Sb₂Te₃ Heterostructures as Probed By Spin Pumping Ferromagnetic Resonance

Abstract

Large‐area antimony telluride (Sb2Te3) thin films are grown by a metal organic chemical vapor deposition technique on 4” Si(111) substrates, and their topological character probed by magnetoconductance measurements. When interfaced with Fe thin films, broadband ferromagnetic resonance spectroscopy (BFMR) shows a clear increase of the damping parameter in Fe/Sb2Te3 when compared to a reference Fe layer, which may suggest the occurrence of spin pumping (SP) into Sb2Te3. Simultaneously, X‐ray reflectivity and conversion electron Mossbauer spectroscopy evidence the development of a chemically and magnetically pure Fe/Sb2Te3 interface. However, by conducting SP‐FMR, it is shown that no spin‐to‐charge conversion (S2C) occurs in Fe/Sb2Te3, while a clear SP signal develops by introducing a 5 nm Au interlayer between Fe and Sb2Te3, with a measured inverse Edelstein effect conversion efficiency of λIEE = 0.27 nm. The results shed some light on the correlation among the chemical‐structural‐magnetic properties of the Fe/Sb2Te3 interface, the broadening of the magnetic damping parameter as detected by BFMR, and the occurrence of S2C, as probed by SP‐FMR.

Significant enhancement of ferromagnetism above room temperature in epitaxial 2D van der Waals ferromagnet Fe5−δGeTe2/Bi2Te3 heterostructures

“…Broadband ferromagnetic resonance (BFMR) experiments were conducted using a home-made facility composed by a Bruker ER-200 electromagnet, an Anritsu-MG3694C radio frequency (RF) source, a Quantum Design grounded coplanar waveguide (GCPW), a Wiltron-70KB50 NEG rectifying diode and a lock-in amplifier. 39,40 During the BFMR measurement, to avoid the shortening of the electrical line, the active part of the GCPW was covered with a 75 μm thick Kapton tape and the sample was placed face down on the GCPW in the so-called "flip-chip" mode. The GCPW and the sample were positioned between the poles of the electromagnet, with the external magnetic field (H) lying parallel to the film plane in the so-called in-plane configuration (IP).…”

Atomically Thin 2D van der Waals Magnetic Materials: Fabrications, Structure, Magnetic Properties and Applications

“…Through broadband ferromagnetic resonance spectroscopy (BFMR) and spin pumping FMR (SP-FMR), they experimentally observed the spin behavior of largearea topological insulators exhibiting spin to charge (S 2 C) with the inverse Edelstein effect (IEE). They found a conversion efficiency of λ IEE ≈ 0.27 nm for Fe/Au/Sb 2 Te 3 , originating from the topologically protected surface states (TSS) of Sb 2 Te 3 [227]. Recently, a spin fieldeffect transistor (SFET) composed of a 2D 2H-VSe 2 magnet was proposed, which could exert a vertical electric field to convert an A-type antiferromagnet into a semimetal [228].…”

Passivation of Bi2Te3 Topological Insulator by Transferred CVD‐Graphene: Toward Intermixing‐Free Interfaces

“…[4] However, to identify the microscopic mechanism of CSI and SOTs, as well as to maximize their efficiency, a deep understanding of the properties of the TI/FM interface is needed. [5][6][7][8][9][10][11] Interface phenomena are complex, involving charge transfer, hybridization, intermixing, or alloying. More so when airsensitive or reactive elements are involved, in which case, oxidation and intermixing are particularly relevant.…”

“…[ 4 ] However, to identify the microscopic mechanism of CSI and SOTs, as well as to maximize their efficiency, a deep understanding of the properties of the TI/FM interface is needed. [ 5–11 ]…”