Defect-induced Magnetism and Transport Phenomena in Epitaxial Oxides

Defect-induced Magnetism and Transport Phenomena in Epitaxial Oxides PDF Author: Frank Schoofs
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
This work focuses on the impact of defects, intrinsic or artificially introduced, on the functional properties of thin, epitaxial oxide films. In the first part, the origin of the ferromagnetic properties of Mn-doped and undoped zinc oxide is studied. The deposition conditions are found to have a significant impact on the structural, transport and magnetic properties of the thin films. Combining x-ray magnetic circular dichroism and magnetometry experiments, it is established that the transition metal dopants (i.e. Mn) have no influence on the ferromagnetic nature of the zinc oxide, but that localised magnetic moments on intrinsic defects are in fact responsible for the ferromagnetic behaviour. A relation between strain (related to defect concentration) and magnetisation is established. In the second part of this dissertation, artificially introduced defects are employed in order to discover the fundamental conduction mechanism behind the two-dimensionally conductive LaAlO3/SrTiO3 interface. All experiments, from varying deposition temperature, to oxygen pressure, to laser fluence or to the insertion of (doped) perovskite layers, point towards a structurally governed conduction mechanism, although the exact details are still unclear. Distinct transitions in the resistance versus temperature curves are observed at different values than the bulk phase transformation temperature. These transitions form the boundaries of different conduction modes, with tendencies towards non-Fermi-liquid behaviour observed in certain two-dimensionally conducting samples in limited temperature regimes. By optimising the (defect) structure at the interface, i.e. by introducing a single unit cell of (La0.5,Sr0.5)TiO3 or SnTiO3, it is shown that the sheet carrier density can be dramatically enhanced, up to an order of magnitude higher than unmodified LaAlO3/SrTiO3 interfaces with a value of 1e14 cm-2 at 200 K. Finally, attempts at functionalising the conductive heterointerface by doping and inserting (anti)ferromagnetic layers are made.

Defect-induced Magnetism and Transport Phenomena in Epitaxial Oxides

Defect-induced Magnetism and Transport Phenomena in Epitaxial Oxides PDF Author: Frank Schoofs
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
This work focuses on the impact of defects, intrinsic or artificially introduced, on the functional properties of thin, epitaxial oxide films. In the first part, the origin of the ferromagnetic properties of Mn-doped and undoped zinc oxide is studied. The deposition conditions are found to have a significant impact on the structural, transport and magnetic properties of the thin films. Combining x-ray magnetic circular dichroism and magnetometry experiments, it is established that the transition metal dopants (i.e. Mn) have no influence on the ferromagnetic nature of the zinc oxide, but that localised magnetic moments on intrinsic defects are in fact responsible for the ferromagnetic behaviour. A relation between strain (related to defect concentration) and magnetisation is established. In the second part of this dissertation, artificially introduced defects are employed in order to discover the fundamental conduction mechanism behind the two-dimensionally conductive LaAlO3/SrTiO3 interface. All experiments, from varying deposition temperature, to oxygen pressure, to laser fluence or to the insertion of (doped) perovskite layers, point towards a structurally governed conduction mechanism, although the exact details are still unclear. Distinct transitions in the resistance versus temperature curves are observed at different values than the bulk phase transformation temperature. These transitions form the boundaries of different conduction modes, with tendencies towards non-Fermi-liquid behaviour observed in certain two-dimensionally conducting samples in limited temperature regimes. By optimising the (defect) structure at the interface, i.e. by introducing a single unit cell of (La0.5,Sr0.5)TiO3 or SnTiO3, it is shown that the sheet carrier density can be dramatically enhanced, up to an order of magnitude higher than unmodified LaAlO3/SrTiO3 interfaces with a value of 1e14 cm-2 at 200 K. Finally, attempts at functionalising the conductive heterointerface by doping and inserting (anti)ferromagnetic layers are made.

Defect-Induced Magnetism in Oxide Semiconductors

Defect-Induced Magnetism in Oxide Semiconductors PDF Author: Parmod Kumar
Publisher: Elsevier
ISBN: 0323909086
Category : Technology & Engineering
Languages : en
Pages : 738

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Book Description
Defect-Induced Magnetism in Oxide Semiconductors provides an overview of the latest advances in defect engineering to create new magnetic materials and enable new technological applications. First, the book introduces the mechanisms, behavior, and theory of magnetism in oxide semiconductors and reviews the methods of inducing magnetism in these materials. Then, strategies such as pulsed laser deposition and RF sputtering to grow oxide nanostructured materials with induced magnetism are discussed. This is followed by a review of the most relevant postdeposition methods to induce magnetism in oxide semiconductors including annealing, ion irradiation, and ion implantation. Examples of defect-induced magnetism in oxide semiconductors are provided along with selected applications. This book is a suitable reference for academic researchers and practitioners and for people engaged in research and development in the disciplines of materials science and engineering. Reviews the magnetic, electrical, dielectric and optical properties of oxide semiconductors with defect-induced magnetism Discusses growth and post-deposition strategies to grow oxide nanostructured materials such as oxide thin films with defect-induced magnetism Provides examples of materials with defect-induced magnetism such as zinc oxide, cerium dioxide, hafnium dioxide, and more

Epitaxial Growth of Complex Metal Oxides

Epitaxial Growth of Complex Metal Oxides PDF Author: Gertjan Koster
Publisher: Elsevier
ISBN: 1782422552
Category : Technology & Engineering
Languages : en
Pages : 505

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Book Description
The atomic arrangement and subsequent properties of a material are determined by the type and conditions of growth leading to epitaxy, making control of these conditions key to the fabrication of higher quality materials. Epitaxial Growth of Complex Metal Oxides reviews the techniques involved in such processes and highlights recent developments in fabrication quality which are facilitating advances in applications for electronic, magnetic and optical purposes. Part One reviews the key techniques involved in the epitaxial growth of complex metal oxides, including growth studies using reflection high-energy electron diffraction, pulsed laser deposition, hybrid molecular beam epitaxy, sputtering processes and chemical solution deposition techniques for the growth of oxide thin films. Part Two goes on to explore the effects of strain and stoichiometry on crystal structure and related properties, in thin film oxides. Finally, the book concludes by discussing selected examples of important applications of complex metal oxide thin films in Part Three. Provides valuable information on the improvements in epitaxial growth processes that have resulted in higher quality films of complex metal oxides and further advances in applications for electronic and optical purposes Examines the techniques used in epitaxial thin film growth Describes the epitaxial growth and functional properties of complex metal oxides and explores the effects of strain and defects

Defects and Transport in Oxides

Defects and Transport in Oxides PDF Author: Martin S. Seltzer
Publisher: Springer
ISBN:
Category : Science
Languages : en
Pages : 640

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Book Description
DEFECTS AND TRANSPORT IN OXIDES is the proceedings of the eighth Battelle Colloquium in the Materials Sciences, held in Columbus and Salt Fork, Ohio, September 17-22, 1973. It took as its theme the relationship between defects and transport of both mass and charge in oxides. Applications of defect-controlled transport to a number of important processes in oxides also were covered. In selecting this topic, the Organizing Committee thought that 1973 was timely to bring together the leading theoretical and experimental researchers in the oxide transport field to review its status in a critical way, and to consider current major research directions and how research in the future might be guided into fruitful areas. The meeting was highlighted by the presentation of several papers which suggest that major advances in our understanding of transport in oxides appear to be imminent. These papers dealt with the results of new theoretical approaches whereby the energies and configurations of defects may be calculated, and with new experimental techniques for indirectly observing these defects, previously thought to be below the limits of experimental resolving power. Other papers, dealing with the application of defect chemistry to technological processes, served to demonstrate the successes and to point out yet unresolved problems associated with ix x PREFACE understanding the chemistry of imperfect crystals.

Defect-induced Magnetism in Non-magnetic Oxides

Defect-induced Magnetism in Non-magnetic Oxides PDF Author: Khalid Muhammad
Publisher:
ISBN:
Category :
Languages : en
Pages : 136

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Chemical Abstracts

Chemical Abstracts PDF Author:
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 2616

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Proceedings of 19th World Congress on Materials Science and Engineering 2018

Proceedings of 19th World Congress on Materials Science and Engineering 2018 PDF Author: ConferenceSeries
Publisher: ConferenceSeries
ISBN:
Category :
Languages : en
Pages : 212

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Book Description
June 11-13, 2018 Barcelona, Spain Key Topics : Materials Science and Engineering, Nanomaterials and Nanotechnology, Biomaterials and Medical Devices, Polymer Science and Technology, Ceramics and Composite Materials, Electronic, Optical and Magnetic Materials, Emerging Smart Materials, Materials for Energy and Environmental Sustainability, Physics and Chemistry of Materials, Metals, Mining, Metallurgy and Materials, Mechanics, Characterization Techniques and Equipments, Graphene and 2D Materials,

Energy Research Abstracts

Energy Research Abstracts PDF Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 508

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Transactions of the Materials Research Society of Japan

Transactions of the Materials Research Society of Japan PDF Author:
Publisher:
ISBN:
Category : Materials
Languages : en
Pages : 740

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Book Description
Issues for 1994-1995 included papers from the IUMRS-ICAM; issues for 1999-2002 include papers for all the symposia sponsored by the MRSJ.

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 704

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