Study of growing incongruent antiferromagnetic single crystals and characterization
type: CreativeWork
description: Antiferromagnets are gaining increased attention as potential spintronic materials with faster switching rates compared to conventional ferromagnets. Recently reported studies have demonstrated partial switching of the Néel vector of antiferromagnetic CuMnAs and Mn2Au with current-induced spin-orbit torques. More intermetallic antiferromagnets share the structure types of CuMnAs and Mn2Au, or at least contain degenerated in-plane magnetic configurations, are proposed as candidates for current-induced magnetic switching. Single crystals of such materials are needed to study the orientation dependence of their magnetic dynamics, but the growth of single crystals of intermetallics is challenging, especially for incongruent candidates that cannot be obtained by conventional solid-state synthesis. Here, multiple synthesis methods for single crystals of the metallic antiferromagnets Fe2As, FeSn, and Cr2Al were investigated. The chemical vapor transport (CVT) has been used to assemble large crystalline grains below their melting/decomposition temperatures. In this thesis, the thermodynamics of these CVT reactions are investigated and presented alongside experimental efforts for single crystals of Fe2As and FeSn. Reasonably reliable predictions and analysis can be attained, but numerous approximations must be main due to unknown entropy and enthalpy for many of the phases involved in a given CVT reaction. Compared to the previously reported models of the intermetallic CVT systems, the proposed reactions provide a more comprehensive means to consider the effective parameters (including the transport agents, the possible intermetallic phases to deposit, and the partial pressures of each individual transport species) for predicting the outcomes of a CVT system. The flux method was used to grow single crystals of Cr2Al, with crystallinity and purity confirmed by X-ray diffraction. The neutron diffraction of a Cr2Al powder sample revealed the magnetic ordering of Cr2Al. The Riet…
abstract: Antiferromagnets are gaining increased attention as potential spintronic materials with faster switching rates compared to conventional ferromagnets. Recently reported studies have demonstrated partial switching of the Néel vector of antiferromagnetic CuMnAs and Mn2Au with current-induced spin-orbit torques. More intermetallic antiferromagnets share the structure types of CuMnAs and Mn2Au, or at least contain degenerated in-plane magnetic configurations, are proposed as candidates for current-induced magnetic switching. Single crystals of such materials are needed to study the orientation dependence of their magnetic dynamics, but the growth of single crystals of intermetallics is challenging, especially for incongruent candidates that cannot be obtained by conventional solid-state synthesis. Here, multiple synthesis methods for single crystals of the metallic antiferromagnets Fe2As, FeSn, and Cr2Al were investigated. The chemical vapor transport (CVT) has been used to assemble large crystalline grains below their melting/decomposition temperatures. In this thesis, the thermodynamics of these CVT reactions are investigated and presented alongside experimental efforts for single crystals of Fe2As and FeSn. Reasonably reliable predictions and analysis can be attained, but numerous approximations must be main due to unknown entropy and enthalpy for many of the phases involved in a given CVT reaction. Compared to the previously reported models of the intermetallic CVT systems, the proposed reactions provide a more comprehensive means to consider the effective parameters (including the transport agents, the possible intermetallic phases to deposit, and the partial pressures of each individual transport species) for predicting the outcomes of a CVT system. The flux method was used to grow single crystals of Cr2Al, with crystallinity and purity confirmed by X-ray diffraction. The neutron diffraction of a Cr2Al powder sample revealed the magnetic ordering of Cr2Al. The Riet…
author: Zhao, Chengxi
language: en
keywords: antiferromagnetic, single crystals, chemical vapor transport, flux method, neutron diffraction.
date published: 2021-09-17T02:34:34Z
date modified: 2026-07-22T22:24:52Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/110690