Tuning Spin Current Injection at Ferromagnet-Nonmagnet Interfaces by Molecular Design

Angela Wittmann, Guillaume Schweicher, Katharina Broch, Jiri Novak, Vincent Lami, David Cornil, Erik R. McNellis, Olga Zadvorna, Deepak Venkateshvaran, Kazuo Takimiya, Yves H. Geerts, Jérôme Cornil, Yana Vaynzof, Jairo Sinova, Shun Watanabe, and Henning Sirringhaus

Phys. Rev. Lett. 124, 027204 – Published 16 January 2020

Abstract

There is a growing interest in utilizing the distinctive material properties of organic semiconductors for spintronic applications. Here, we explore the injection of pure spin current from Permalloy into a small molecule system based on dinaphtho[2,3-b:2,3-f]thieno[3,2-b]thiophene (DNTT) at ferromagnetic resonance. The unique tunability of organic materials by molecular design allows us to study the impact of interfacial properties on the spin injection efficiency systematically. We show that both the spin injection efficiency at the interface and the spin diffusion length can be tuned sensitively by the interfacial molecular structure and side chain substitution of the molecule.

Received 14 February 2019
Revised 18 September 2019

DOI:https://doi.org/10.1103/PhysRevLett.124.027204

Physics Subject Headings (PhySH)

Spin diffusion Spin injection Spin pumping Spintronics

Ferromagnets Organic semiconductors

Density functional theory Ferromagnetic resonance Ultraviolet photoelectron spectroscopy X-ray techniques

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Angela Wittmann ¹, Guillaume Schweicher ¹, Katharina Broch², Jiri Novak³, Vincent Lami^4,5, David Cornil⁶, Erik R. McNellis⁷, Olga Zadvorna¹, Deepak Venkateshvaran¹, Kazuo Takimiya⁸, Yves H. Geerts⁹, Jérôme Cornil⁶, Yana Vaynzof^4,5, Jairo Sinova⁷, Shun Watanabe¹⁰, and Henning Sirringhaus¹

¹Optoelectronics Group, Cavendish Laboratory, University of Cambridge, J. J. Thompson Avenue, Cambridge CB3 0HE, United Kingdom
²Institut für Angewandte Physik, Universität Tübingen, Aufder Morgenstelle 10, 72076 Tübingen, Germany
³CEITEC MU and Faculty of Science, Masaryk University, 61137 Brno, Czech Republic
⁴Kirchhof Institute for Physics, Im Neuenheimer Feld 227, Heidelberg University, 69120 Heidelberg, Germany
⁵Centre for Advanced Materials, Im Neuenheimer Feld 225, Heidelberg University, 69120 Heidelberg, Germany
⁶Laboratory for Chemistry of Novel Materials, University of Mons, 7000 Mons, Belgium
⁷Institute of Physics, Johannes Gutenberg-Universität, 55128 Mainz, Germany
⁸RIKEN Center for Emergent Matter Science, Wako, Saitama 351-0198, Japan
⁹Laboratoire de Chimie des Polymères, Université Libre de Bruxelles, 1050 Bruxelles, Belgium
¹⁰Department of Advanced Materials Science, School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan

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Issue

Vol. 124, Iss. 2 — 17 January 2020

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