Engineering Dzyaloshinskii-Moriya interaction in B20 thin-film chiral magnets

Emrah Turgut, Hanjong Paik, Kayla Nguyen, David A. Muller, Darrell G. Schlom, and Gregory D. Fuchs

Phys. Rev. Materials 2, 074404 – Published 16 July 2018

Abstract

Chiral magnetic $M n_{x} F e_{1 - x} Ge$ compounds have an antisymmetric exchange interaction that is tunable with the manganese stoichiometric fraction, $x$ . Although millimeter-scale, polycrystalline bulk samples of this family of compounds have been produced, thin-film versions of these materials will be necessary for devices. In this study, we demonstrate the growth of epitaxial $M n_{x} F e_{1 - x} Ge$ thin films on Si(111) substrates with a pure B20 crystal structure in the stoichiometric fraction range $x$ from 0 to 0.81. Following systematic structural analysis and magnetic characterization consisting of dc magnetization measurements and microwave absorption spectroscopy, we quantify the antisymmetric exchange interaction and helical period as a function of $x$ , which ranges from 200 nm to 8 nm. Our results demonstrate an approach to engineering the size of magnetic skyrmions in epitaxial films that are grown using scalable techniques.

Received 13 February 2018
Revised 26 May 2018

DOI:https://doi.org/10.1103/PhysRevMaterials.2.074404

Physics Subject Headings (PhySH)

Helicoidal magnetic texture Magnetism Skyrmions

Ferromagnetic resonance Molecular beam epitaxy

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Emrah Turgut¹, Hanjong Paik^2,3, Kayla Nguyen¹, David A. Muller^1,4, Darrell G. Schlom^2,4, and Gregory D. Fuchs^1,4,*

¹School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA
²Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA
³Platform for the Accelerated Realization, Analysis, & Discovery of Interface Materials (PARADIM), Cornell University, Ithaca, New York 14853, USA
⁴Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, USA