Engineering Properties of Transition Metal Halides via Cationic Alloying

abstract: Transition metal di- and tri-halides (TMH) have recently gathered research attention owing to their intrinsic magnetism all the way down to their two-dimensional limit. 2D magnets, despite being a crucial component for realizing van der Waals heterostructures and devices with various funct...

Full description

Bibliographic Details
Other Authors: Kolari, Pranvera (Author)
Format: Dissertation
Language:English
Published: 2020
Subjects:
Online Access:http://hdl.handle.net/2286/R.I.62797
id ndltd-asu.edu-item-62797
record_format oai_dc
spelling ndltd-asu.edu-item-627972020-12-09T05:00:43Z Engineering Properties of Transition Metal Halides via Cationic Alloying abstract: Transition metal di- and tri-halides (TMH) have recently gathered research attention owing to their intrinsic magnetism all the way down to their two-dimensional limit. 2D magnets, despite being a crucial component for realizing van der Waals heterostructures and devices with various functionalities, were not experimentally proven until very recently in 2017. The findings opened up enormous possibilities for studying new quantum states of matter that can enable potential to design spintronic, magnetic memory, data storage, sensing, and topological devices. However, practical applications in modern technologies demand materials with various physical and chemical properties such as electronic, optical, structural, catalytic, magnetic etc., which cannot be found within single material systems. Considering that compositional modifications in 2D systems lead to significant changes in properties due to the high anisotropy inherent to their crystallographic structure, this work focuses on alloying of TMH compounds to explore the potentials for tuning their properties. In this thesis, the ternary cation alloys of Co(1-x)Ni(x)Cl(2) and Mo(1-x)Cr(x)Cl(3) were synthesized via chemical vapor transport at a various stoichiometry. Their compositional, structural, and magnetic properties were studied using Energy Dispersive Spectroscopy, Raman Spectroscopy, X-Ray Diffraction, and Vibrating Sample Magnetometry. It was found that completely miscible ternary alloys of Co(1-x)Ni(x)Cl(2) show an increasing Néel temperature with nickel concentration. The Mo(1-x)Cr(x)Cl(3) alloy shows potential magnetic phase changes induced by the incorporation of molybdenum species within the host CrCl3 lattice. Magnetic measurements give insight into potential antiferromagnetic to ferromagnetic transition with molybdenum incorporation, accompanied by a shift in the magnetic easy-axis from parallel to perpendicular. Phase separation was found in the Fe(1-x)Cr(x)Cl(3) ternary alloy indicating that crystallographic structure compatibility plays an essential role in determining the miscibility of two parent compounds. Alloying across two similar (TMH) compounds appears to yield predictable results in properties as in the case of Co(1-x)Ni(x)Cl(2), while more exotic transitions, as in the case of Mo(1-x)Cr(x)Cl(3), can emerge by alloying dissimilar compounds. When dissimilarity reaches a certain limit, as with Fe(1-x)Cr(x)Cl(3), phase separation becomes more favorable. Future studies focusing on magnetic and structural phase transitions will reveal more insight into the effect of alloying in these TMH systems. Dissertation/Thesis Kolari, Pranvera (Author) Tongay, Sefaattin (Advisor) Jiao, Yang (Committee member) Muhich, Christopher (Committee member) Arizona State University (Publisher) Materials Science 2D Magnets 2D Materials Alloying Chemical Vapor Transport Material Synthesis Transition Metal Halides eng 111 pages Masters Thesis Materials Science and Engineering 2020 Masters Thesis http://hdl.handle.net/2286/R.I.62797 http://rightsstatements.org/vocab/InC/1.0/ 2020
collection NDLTD
language English
format Dissertation
sources NDLTD
topic Materials Science
2D Magnets
2D Materials
Alloying
Chemical Vapor Transport
Material Synthesis
Transition Metal Halides
spellingShingle Materials Science
2D Magnets
2D Materials
Alloying
Chemical Vapor Transport
Material Synthesis
Transition Metal Halides
Engineering Properties of Transition Metal Halides via Cationic Alloying
description abstract: Transition metal di- and tri-halides (TMH) have recently gathered research attention owing to their intrinsic magnetism all the way down to their two-dimensional limit. 2D magnets, despite being a crucial component for realizing van der Waals heterostructures and devices with various functionalities, were not experimentally proven until very recently in 2017. The findings opened up enormous possibilities for studying new quantum states of matter that can enable potential to design spintronic, magnetic memory, data storage, sensing, and topological devices. However, practical applications in modern technologies demand materials with various physical and chemical properties such as electronic, optical, structural, catalytic, magnetic etc., which cannot be found within single material systems. Considering that compositional modifications in 2D systems lead to significant changes in properties due to the high anisotropy inherent to their crystallographic structure, this work focuses on alloying of TMH compounds to explore the potentials for tuning their properties. In this thesis, the ternary cation alloys of Co(1-x)Ni(x)Cl(2) and Mo(1-x)Cr(x)Cl(3) were synthesized via chemical vapor transport at a various stoichiometry. Their compositional, structural, and magnetic properties were studied using Energy Dispersive Spectroscopy, Raman Spectroscopy, X-Ray Diffraction, and Vibrating Sample Magnetometry. It was found that completely miscible ternary alloys of Co(1-x)Ni(x)Cl(2) show an increasing Néel temperature with nickel concentration. The Mo(1-x)Cr(x)Cl(3) alloy shows potential magnetic phase changes induced by the incorporation of molybdenum species within the host CrCl3 lattice. Magnetic measurements give insight into potential antiferromagnetic to ferromagnetic transition with molybdenum incorporation, accompanied by a shift in the magnetic easy-axis from parallel to perpendicular. Phase separation was found in the Fe(1-x)Cr(x)Cl(3) ternary alloy indicating that crystallographic structure compatibility plays an essential role in determining the miscibility of two parent compounds. Alloying across two similar (TMH) compounds appears to yield predictable results in properties as in the case of Co(1-x)Ni(x)Cl(2), while more exotic transitions, as in the case of Mo(1-x)Cr(x)Cl(3), can emerge by alloying dissimilar compounds. When dissimilarity reaches a certain limit, as with Fe(1-x)Cr(x)Cl(3), phase separation becomes more favorable. Future studies focusing on magnetic and structural phase transitions will reveal more insight into the effect of alloying in these TMH systems. === Dissertation/Thesis === Masters Thesis Materials Science and Engineering 2020
author2 Kolari, Pranvera (Author)
author_facet Kolari, Pranvera (Author)
title Engineering Properties of Transition Metal Halides via Cationic Alloying
title_short Engineering Properties of Transition Metal Halides via Cationic Alloying
title_full Engineering Properties of Transition Metal Halides via Cationic Alloying
title_fullStr Engineering Properties of Transition Metal Halides via Cationic Alloying
title_full_unstemmed Engineering Properties of Transition Metal Halides via Cationic Alloying
title_sort engineering properties of transition metal halides via cationic alloying
publishDate 2020
url http://hdl.handle.net/2286/R.I.62797
_version_ 1719368817352638464