Van der Waals magnetic materials for spintronic device applications

Layered van der Waals (vdW) materials have attracted great attention for both their unique physical properties and potential applications in advanced devices. 2D magnets represent a new and rapidly growing family of materials that are being studied for spintronics. In addition to ferromagnets, non-magnetic 2D materials with strong spin orbit coupling and exotic symmetry also hold promise. In the first chapter I will briefly discuss magnetic devices in general, including the history and current state of the art. I will also introduce 2D magnetic materials, with an emphasis on the iron germanium/gallium telluride (FGT) family. In the second chapter I will introduce experimental work using electrical transport to systematically characterize 2D magnets. This includes the use of magnetotransport to unveil competing magnetic phases in iron germanium telluride as shown by the material's temperature dependent transport properties, planar Hall response, and field cooling divergence. The third chapter will entail a discussion of magnetic proximity effects observed in vdW heterostructures. Results showing how iron germanium telluride/platinum heterostructures exhibited unexpected emergent behavior will be presented. This includes changes such as wider hysteresis, steeper reversal, and larger magnetoresistance. The fourth chapter will present a study of MoTe2 films grown using MOCVD for spin orbit torque applications. We demonstrate highly efficient spin-charge conversion in wafer scale 1T' films grown in a back-end-of-line (BEOL) compatible process. The last chapter focuses on 2D multiferroics. I will present efforts to realize an artificial vdW multiferroic comprised of discrete ferromagnetic and ferroelectric components as well as discussions on the design considerations of such structures. I will also introduce results of a study of heterostructures incorporating the intrinsic vdW multiferroic NiI2 and graphene. These structures allow for the electrical characterization of the otherwise insulating helimagnet NiI2.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Chyczewski, Stasiu Thomas

Contributors dc:contributor

• Zhu, Wenjuan
• Hoffmann, Axel F
• Rakheja, Shaloo
• Lyding, Joseph W.

• Magnetic Materials
• 2d Materials
• Spintronics
• Vdw Materials
• Microtechnology
• Nanotechnology

Statement dc:rights

• Copyright 2025 Stasiu Chyczewski

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/130109

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F130109