RUcore: Rutgers University Community Repository
Interplay of strain, polarization and magnetic ordering in complex oxides from first principles
Descriptive
TypeOfResource
Text
TitleInfo
(ID = T-1)
Title
Interplay of strain, polarization and magnetic ordering in complex oxides from first principles
Identifier
ETD_2527
Identifier
(type = hdl)
http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.000053023
Language
LanguageTerm
(authority = ISO639-2);
(type = code)
eng
Genre
(authority = marcgt)
theses
Subject
(ID = SBJ-1);
(authority = RUETD)
Topic
Physics and Astronomy
Subject
(ID = SBJ-2);
(authority = ETD-LCSH)
Topic
Oxides
Subject
(ID = SBJ-3);
(authority = ETD-LCSH)
Topic
Oxides--Analysis
Abstract
(type = abstract)
We study mechanisms of structural and magnetic phase transitions in crystalline oxides from first principles. The focus is on epitaxial stabilization in perovskites and on magnetoelastic coupling and frustration in spinels. These materials and phenomena are of great interest for basic science and have important roles to play in the design and discovery of new functional materials. The effects of epitaxial strain on the structure of the perovskite oxide CaTiO3 are investigated. Particular attention is paid to the stabilization of a ferroelectric phase related to the polar instability found in previous first-principles studies of calcium titanate in the ideal cubic perovskite structure. At 1.5% strain, we find an epitaxial orientation transition between the ab-ePbnm phase, favoured for compressive strains, and the c-ePbnm phase. For larger tensile strains, a polar instability, which was hidden in the equilibrium bulk structure, develops in the c-ePbnm phase and an epitaxial-strain-induced ferroelectric phase is obtained with polarization along a [110] direction with respect to the primitive perovskite lattice vectors of the square substrate. A ferroelectric rhombohedral R3c phase, with a different combination of octahedral rotations, is also found to be competitive in energy for large tensile strains, and might be observable under the application of additional perturbations, such as a small degree of cation substitution. We present an ongoing project to construct a first-principles effective Hamiltonian to investigate the transition from the high-temperature cubic phase to a low-temperature low-symmetry phase observed in the spinel structure oxides CdCr2O4 and ZnCr2O4. The local modes included in the expansion are the chromium displacements, distortions of the cadmium- or zinc-centred tetrahedra, and the homogeneous strain. The magnetostructural coupling of these degrees of freedom to the spins of the chromium ions is included in the effective Hamiltonian parametrization and first-principles determination using a symmetry analysis. The role of the magnetostructural coupling in the phase transition is analysed and discussed.
PhysicalDescription
Form
(authority = gmd)
electronic resource
Extent
v, 65 p. : ill.
InternetMediaType
application/pdf
InternetMediaType
text/xml
Note
(type = degree)
Ph.D.
Note
Includes abstract
Note
Vita
Note
(type = bibliography)
Includes bibliographical references
Note
(type = statement of responsibility)
by Carl-Johan Eklund
Name
(ID = NAME-1);
(type = personal)
NamePart
(type = family)
Eklund
NamePart
(type = given)
Carl-Johan
Role
RoleTerm
(authority = RULIB)
author
DisplayForm
Carl-Johan Eklund
Name
(ID = NAME-2);
(type = personal)
NamePart
(type = family)
Rabe
NamePart
(type = given)
Karin M
Role
RoleTerm
(authority = RULIB)
chair
Affiliation
Advisory Committee
DisplayForm
Karin M Rabe
Name
(ID = NAME-3);
(type = personal)
NamePart
(type = family)
Langreth
NamePart
(type = given)
David C
Role
RoleTerm
(authority = RULIB)
internal member
Affiliation
Advisory Committee
DisplayForm
David C Langreth
Name
(ID = NAME-4);
(type = personal)
NamePart
(type = family)
Kotliar
NamePart
(type = given)
Gabriel
Role
RoleTerm
(authority = RULIB)
internal member
Affiliation
Advisory Committee
DisplayForm
Gabriel Kotliar
Name
(ID = NAME-5);
(type = personal)
NamePart
(type = family)
Kiryukhin
NamePart
(type = given)
Valery
Role
RoleTerm
(authority = RULIB)
internal member
Affiliation
Advisory Committee
DisplayForm
Valery Kiryukhin
Name
(ID = NAME-6);
(type = personal)
NamePart
(type = family)
Hamann
NamePart
(type = given)
Donald R
Role
RoleTerm
(authority = RULIB)
outside member
Affiliation
Advisory Committee
DisplayForm
Donald R Hamann
Name
(ID = NAME-1);
(type = corporate)
NamePart
Rutgers University
Role
RoleTerm
(authority = RULIB)
degree grantor
Name
(ID = NAME-2);
(type = corporate)
NamePart
Graduate School - New Brunswick
Role
RoleTerm
(authority = RULIB)
school
OriginInfo
DateCreated
(qualifier = exact)
2010
DateOther
(qualifier = exact);
(type = degree)
2010
Place
PlaceTerm
(type = code)
xx
RelatedItem
(type = host)
TitleInfo
Title
Rutgers University Electronic Theses and Dissertations
Identifier
(type = RULIB)
ETD
RelatedItem
(type = host)
TitleInfo
Title
Graduate School - New Brunswick Electronic Theses and Dissertations
Identifier
(type = local)
rucore19991600001
Location
PhysicalLocation
(authority = marcorg);
(displayLabel = Rutgers, The State University of New Jersey)
NjNbRU
Identifier
(type = doi)
doi:10.7282/T3GH9J2J
Genre
(authority = ExL-Esploro)
ETD doctoral
Back to the top
Rights
RightsDeclaration
(AUTHORITY = GS);
(ID = rulibRdec0006)
The author owns the copyright to this work.
Copyright
Status
Copyright protected
Availability
Status
Open
Reason
Permission or license
RightsHolder
(ID = PRH-1);
(type = personal)
Name
FamilyName
Eklund
GivenName
Carl-Johan
Role
Copyright Holder
RightsEvent
(ID = RE-1);
(AUTHORITY = rulib)
Type
Permission or license
DateTime
2010-04-02 16:25:04
AssociatedEntity
(ID = AE-1);
(AUTHORITY = rulib)
Role
Copyright holder
Name
Carl-Johan Eklund
Affiliation
Rutgers University. Graduate School - New Brunswick
AssociatedObject
(ID = AO-1);
(AUTHORITY = rulib)
Type
License
Name
Author Agreement License
Detail
I hereby grant to the Rutgers University Libraries and to my school the non-exclusive right to archive, reproduce and distribute my thesis or dissertation, in whole or in part, and/or my abstract, in whole or in part, in and from an electronic format, subject to the release date subsequently stipulated in this submittal form and approved by my school. I represent and stipulate that the thesis or dissertation and its abstract are my original work, that they do not infringe or violate any rights of others, and that I make these grants as the sole owner of the rights to my thesis or dissertation and its abstract. I represent that I have obtained written permissions, when necessary, from the owner(s) of each third party copyrighted matter to be included in my thesis or dissertation and will supply copies of such upon request by my school. I acknowledge that RU ETD and my school will not distribute my thesis or dissertation or its abstract if, in their reasonable judgment, they believe all such rights have not been secured. I acknowledge that I retain ownership rights to the copyright of my work. I also retain the right to use all or part of this thesis or dissertation in future works, such as articles or books.
Back to the top
Technical
ContentModel
ETD
MimeType
(TYPE = file)
application/pdf
MimeType
(TYPE = container)
application/x-tar
FileSize
(UNIT = bytes)
675840
Checksum
(METHOD = SHA1)
143df60874878d3dcd953a6531a89c80bd0ffc5c
Back to the top
Statistical Profile