Phase relations, single crystal growth, and characterization of metallic antiferromagnets
Gebre, Mebatsion Sileshi
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/120429
Description
Title
Phase relations, single crystal growth, and characterization of metallic antiferromagnets
Author(s)
Gebre, Mebatsion Sileshi
Issue Date
2023-04-27
Director of Research (if dissertation) or Advisor (if thesis)
Shoemaker, Daniel P
Doctoral Committee Chair(s)
Shoemaker, Daniel P
Committee Member(s)
Hoffmann, Axel
Schleife, Andre
Mahmood, Fahad
Department of Study
Materials Science & Engineerng
Discipline
Materials Science & Engr
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Metallic antiferromagnets
crystal growth
magnetocrystalline anisotropy
Abstract
Metallic antiferromagnets (AFM) are actively researched in materials science and physics
as spintronic material candidates and for emerging physical phenomena. Understanding the
phase relations in relevant chemical systems to grow and characterize high quality AFM single
crystals is integral to learning their fundamental physical and magnetic properties. Magnetic
ordering can be studied in materials containing transition 3d metals or in lanthanide-containing
compounds. In this work, two families of materials that host metallic or topological
insulator AFM of interest in the Eu-Sn-In-P and Mn-Au-Bi systems are studied. Special
focus is afforded to exploring the phase stability, property-targeted chemical modifications,
single crystal growth, and anisotropic characterization of magnetic properties.
The high temperature metallic antiferromagnet Mn2Au, has been proposed as a suitable
candidate for spintronics applications via several prior thin-film and polycrystal studies,
as well as first principles calculations. In this work, a single crystal growth method was
developed and optimized using bismuth flux to obtain the first mm-scaled bulk single crystals
of the material. The phase purity, nuclear and magnetic structures, crystal orientations,
magnetic anisotropy and electric transport properties of the single crystals are discussed in
comparison to existing literature.
Chemical substitution targeting materials discovery and band structure engineering in the
magnetic topological insulator candidate, EuSn2P2, is explored using experimental substitutions
on the Eu and Sn sites, informed by a review of the literature and density functional
theory calculations (DFT). Partial alloying in the Eu(Sn/In)2P2 system is confirmed and
proposed as an alternative route towards chemically tuning the band structure of EuSn2P2.The structure of a new quaternary phase, orthorhombic Eu2InSnP3, is solved as an addition
to this phase space. The intrinsic material properties of these materials are probed on single
crystals using a variety of transport, magnetic properties, and spectroscopy techniques.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
