December 1 - 6, 2024
Boston, Massachusetts
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2024 MRS Fall Meeting & Exhibit
QT02.11.03

Unraveling the Role of Au and Al Interlayers in Observing Spin-Charge Conversion in Sb2Te3 Topological Insulator

When and Where

Dec 5, 2024
9:30am - 9:45am
Sheraton, Fifth Floor, Public Garden

Presenter(s)

Co-Author(s)

Emanuele Longo1,2,Matteo Belli2,Claudia Wiemer2,Alessio Lamperti2,Andrey Matetskiy2,Polina Sheverdyaeva2,Paolo Moras2,Marco Fanciulli3,Roberto Mantovan2

Universitat Autònoma de Barcelona1,Consiglio Nazionale delle Ricerche2,University of Milano-Bicocca3

Abstract

Emanuele Longo1,2,Matteo Belli2,Claudia Wiemer2,Alessio Lamperti2,Andrey Matetskiy2,Polina Sheverdyaeva2,Paolo Moras2,Marco Fanciulli3,Roberto Mantovan2

Universitat Autònoma de Barcelona1,Consiglio Nazionale delle Ricerche2,University of Milano-Bicocca3
Topological insulators (TIs) can be used to control the magnetization of ferromagnetic (FM) layers in TI/FM heterostructures through spin-charge conversion (SCC) mechanisms driven by the topological surface state (TSS).<sup>1</sup> Non-magnetic interlayers at the TI/FM interface are frequently employed to enhance SCC efficiency, as demonstrated in Sb<sub>2</sub>Te<sub>3</sub>/Au/Co(Fe) heterostructures.<sup>2,3</sup> However, the effect of Au on the TSS of Sb<sub>2</sub>Te<sub>3</sub> was not fully characterized.<br/>Here, we study the different impact of Al and Au interlayers at the interface of Sb<sub>2</sub>Te<sub>3</sub>/Co heterostructures. Spin pumping experiments show that SCC is not observed in the presence of Al, in net contrast to the use of Au.<sup>2,3</sup> To understand the origin of this behavior, in-situ X-ray Photoemission Spectroscopy and Angle-Resolved Photoemission Spectroscopy measurements with synchrotron radiation were conducted during the deposition of Al and Au thin films on the Sb<sub>2</sub>Te<sub>3</sub> surface. The analysis reveals the highly reactive character of Al and the disappearance of TSS upon deposition of only 1 nm thick Al film, at variance with the case of Au, which preserves the TSS.<br/>These findings highlight the critical choice of non-magnetic material interlayers in devices for SCC applications and underscore the importance of preserving the TSS for efficient device performance.<br/><br/><b>Bibliography</b><br/>1. Hirohata, A. <i>et al.</i> Review on spintronics: Principles and device applications. <i>J Magn Magn Mater</i> <b>509</b>, 166711 (2020).<br/>2. Longo, E. <i>et al.</i> Spin-Charge Conversion in Fe/Au/Sb 2 Te 3 Heterostructures as Probed By Spin Pumping Ferromagnetic Resonance. <i>Adv Mater Interfaces</i> <b>2101244</b>, 2101244 (2021).<br/>3. Longo, E. <i>et al.</i> Large Spin-to-Charge Conversion at Room Temperature in Extended Epitaxial Sb2Te3 Topological Insulator Chemically Grown on Silicon. <i>Adv Funct Mater</i> <b>2109361</b>, (2021).

Keywords

interface

Symposium Organizers

Chiara Ciccarelli, University of Cambridge
Tobias Kampfrath, Freie Universität Berlin
Roberto Mantovan, CNR-IMM, Univ of Agrate Brianza
Jianhua Zhao, Chinese Academy of Sciences

Session Chairs

Manuel Bibes

In this Session