Exploring the Structural, Electronic, and Magnetoresponsive Properties of Novel Magnetic Materials in Bulk, Ribbons, and Thin Films PDF Download

Author: Sudip Pandey
Publisher:
ISBN:
Category : Ribbons
Languages : en
Pages : 430

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Author: Jennifer Rose Soliz
Publisher:
ISBN:
Category :
Languages : en
Pages : 249

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Abstract: In this entire work, we characterize the structural, electrical, and magnetic properties of many novel magnetic polycrystalline materials. Our focus is to investigate these properties to enhance the scientific community and possibly pave the road to explore into other directions, such as growing thin films. we investigate the effect of charge carrier substitution with chemical disorder for Ca1-xLaxMn0.5Ru0.5O3 (x = 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, and 0.0) double perovskites. X-ray diffraction measurements showed these polycrystalline powders to be phase pure and to exhibit Pnma symmetry with a b+a- octahedral tilting. Neutron powder diffraction (NPD) showed that the crystal structure and magnetic moments do not change significantly across the substitution range. Ca0.5La0.5Mn0.5Ru0.5O3 exhibits ferrimagnetism. NPD further concluded the lack of cooperative Jahn Teller distortion. Density functional theory (DFT) calculations confirmed that the extra 1/2 electron is responsible for opening the band gap, in that 0.295e and 0.17e is being transferred to the Ru and Mn bands, respectively. Thus, the Fermi level is being tuned when La3+ is substituted into the system. DFT calculations also showed ferrimagnetism to be the most energetically stable magnetic phase. Overall we conclude that despite the chemical disorder, Ca0.5La0.5Mn0.5Ru0.5O3 is an insulating ferrimagnet with a Curie temperature (TC) of 233 K, which is a rare finding to have chemical disorder with magnetic order. The next chapter, we examine the effects of isovalent substitution in Ba1-xSrxMn0.5Ru0.5O3 system. We explore how the larger cation, Ba2+, impacts the structural, electrical, and magnetic properties. We find that BaMn0.5Ru0.5O3 crystallizes in the 9R polymorph with R-3m symmetry. BaMn0.5Ru0.5O3 is an insulating canted antiferromagnet with a TN of 36 K. From neutron diffraction, Mn1 and Mn2 have magnetic moment values of 1.60(4) uB/f.u. and 2.15(2) uB/f.u., respectively. For simplicity, the Ru moments were not refined. While the refined moments are low for Mn3+/4+, it is assumed that Ru is contributing to the magnetic moments. Ba0.5Sr0.5Mn0.5Ru0.5O3 crystallizes with the 6H crystal structure which has P63/mmc symmetry. From low temperature neutron diffraction, Ba0.5Sr0.5Mn0.5Ru0.5O3 exhibits glassy behavior since it lacks long range magnetic order. Resistivity measurements show this compound to be an insulator. In the following chapter, we continue studying Ba1-xAxMn0.5Ru0.5O3 perovskites by substituting in charge carriers. We explore the effects of aliovalent substitution, La3+, by investigating the structural, magnetic, and electrical properties for the phase diagram of Ba1 xLaxMn0.5Ru0.5O3 system. The end members were found to be phase pure solid solutions while the in between compositions were heterogeneous mixtures. While BaMn0.5Ru0.5O3 exhibits the 9R as noted above, Ba0.5La0.5Mn0.5Ru0.5O3 manifests the 3C (I4/mcm space group symmetry) crystal structure and is an insulating ferrimagnet with a TC of 205 K. From neutron diffraction, both the ferromagnetic and ferrimagnetic structures have similar refinement values. However, the moments obtained from a ferrimagnetic structure (Mn = 3.7 uB/f.u. and Ru = -0.88(2) uB/f.u.) are more reasonable than for a ferromagnetic structure (Mn = 1.707(7) uB/f.u. and Ru = 1.707(7) uB/f.u.). Plus the magnetization shows Ba0.5La0.5Mn0.5Ru0.5O3 to have 1.54 uB/f.u., which is closer in value to the expected spin only ferrimagnetic moment for Mn3+ + Ru4+ oxidation states. Thus we conclude that Ba0.5La0.5Mn0.5Ru0.5O3 is a ferrimagnet based on the refined magnetic moments gathered from neutron diffraction and the magnetization results from SQUID. Thin films of Sr2CrReO6 have been reported to be metallic (possibly half-metallic) with a high Curie temperature (635K), which makes this material a feasible candidate for spintronic applications. To understand the role of doping, investigations of the structural, electrical, and magnetic properties of on and off stoichiometric Sr2+xCrReO6 (x = -0.07, 0.0, 0.05, 0.075, and 0.10), Sr2Cr1+yRe1 yO6 (y = 0.1, 0.05, 0.05, and 0.1), and A-site substituted Sr2-zAzCrReO6 (A = K, Ca, and La; z = 0.10 and 0.20; z = 1.0 only for Ca) samples have been achieved. Varying the Cr/Re ratio and aliovalent substitutions on the A-site lead to systematic variations in the magnetization and Curie temperatures. As the Re oxidation state increases, the saturation magnetization increases and the Curie temperature decreases. In the last chapter, we investigate the structural, magnetic, and electrical properties of phase pure polycrystalline Sr2CrOsO6. From X-ray powder diffraction, Sr2CrOsO6 adopts the symmetry and is 73.6(3) % ordered. Our magnetic results show Sr2CrOsO6 to be a ferrimagnet with a small net moment of 0.224 uB/f.u. and the coercitivity to be 7.84 T at 4.5 K in a field strength of 35 T, and the Curie temperature is 660 K. Sr2CrOsO6 is strongly insulating with resistivity of 0.0861 [omega]*cm at 300 K and shows activated electron transport.

Author: Andreas Kaidatzis
Publisher: Springer Nature
ISBN: 9402420347
Category : Science
Languages : en
Pages : 171

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Book Description
Magnetic and spintronic materials are ubiquitous in modern technological applications, e.g. in electric motors, power generators, sensors and actuators, not to mention information storage and processing. Medical technology has also greatly benefited from magnetic materials – especially magnetic nanoparticles – for therapy and diagnostics methods. All of the above-mentioned applications rely on the properties of the materials used. These properties in turn depend on intrinsic and extrinsic material parameters. The former are related to the actual elements used and their properties, e.g. atomic magnetic moment and exchange interaction between atoms; the latter are related to the structural and microstructural properties of the materials used, e.g. their crystal structure, grain size, and grain boundary phases. Focusing on state-of-the-art magnetic and spintronic materials, this book will introduce readers to a range of related topics in Physics and Materials Science. Phenomena and processes at the nanoscale are of particular importance in this context; accordingly, much of the book addresses such topics.

Author: Yi Liu
Publisher: Springer Science & Business Media
ISBN: 1402079842
Category : Science
Languages : en
Pages : 1844

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In December 2002, the world's first commercial magnetic levitation super-train went into operation in Shanghai. The train is held just above the rails by magnetic levitation (maglev) and can travel at a speed of 400 km/hr, completing the 30km journey from the city to the airport in minutes. Now consumers are enjoying 50 GB hard drives compared to 0.5 GB hard drives ten years ago. Achievements in magnetic materials research have made dreams of a few decades ago reality. The objective of the four volume reference, Handbook of Advanced Magnetic Materials, is to provide a comprehensive review of recent progress in magnetic materials research. Each chapter will have an introduction to give a clear definition of basic and important concepts of the topic. The details of the topic are then elucidated theoretically and experimentally. New ideas for further advancement are then discussed. Sufficient references are also included for those who wish to read the original work. In the last decade, one of the most significant thrust areas of materials research has been nanostructured magnetic materials. There are several critical sizes that control the behavior of a magnetic material, and size effects become especially critical when dimensions approach a few nanometers, where quantum phenomena appear. The first volume of the book, Nanostructured Advanced Magnetic Materials, has therefore been devoted to the recent development of nanostructured magnetic materials, emphasizing size effects. Our understanding of magnetism has advanced with the establishment of the theory of atomic magnetic moments and itinerant magnetism. Simulation is a powerful tool for exploration and explanation of properties of various magnetic materials. Simulation also provides insight for further development of new materials. Naturally, before any simulation can be started, a model must be constructed. This requires that the material be well characterized. Therefore the second volume, Characterization and Simulation provides a comprehensive review of both experimental methods and simulation techniques for the characterization of magnetic materials. After an introduction, each section gives a detailed description of the method and the following sections provide examples and results of the method. Finally further development of the method will be discussed. The success of each type of magnetic material depends on its properties and cost which are directly related to its fabrication process. Processing of a material can be critical for development of artificial materials such as multilayer films, clusters, etc. Moreover, cost-effective processing usually determines whether a material can be commercialized. In recent years processing of materials has continuously evolved from improvement of traditional methods to more sophisticated and novel methods. The objective of the third volume, Processing of Advanced Magnetic Materials, is to provide a comprehensive review of recent developments in processing of advanced magnetic materials. Each chapter will have an introduction and a section to provide a detailed description of the processing method. The following sections give detailed descriptions of the processing, properties and applications of the relevant materials. Finally the potential and limitation of the processing method will be discussed. The properties of a magnetic material can be characterized by intrinsic properties such as anisotropy, saturation magnetization and extrinsic properties such as coercivity. The properties of a magnetic material can be affected by its chemical composition and processing route. With the continuous search for new materials and invention of new processing routes, magnetic properties of materials cover a wide spectrum of soft magnetic materials, hard magnetic materials, recording materials, sensor materials and others. The objective of the fourth volume, Properties and Applications of Advanced Magnetic Materials, is to provide a comprehensive review of recent development of various magnetic materials and their applications. Each chapter will have an introduction of the materials and the principles of their applications. The following sections give a detailed description of the processing, properties and applications. Finally the potential and limitation of the materials will be discussed.

Author: Bretislav Heinrich
Publisher: Springer Science & Business Media
ISBN: 354027166X
Category : Science
Languages : en
Pages : 362

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The ability to understand and control the unique properties of interfaces has created an entirely new field of magnetism, with profound impact in technology and serving as the basis for a revolution in electronics. Our understanding of the physics of magnetic nanostructures has also advanced significantly. This rapid development has generated a need for a comprehensive treatment that can serve as an introduction to the field for those entering it from diverse fields, but which will also serve as a timely overview for those already working in this area. The four-volume work Ultra-Thin Magnetic Structures aims to fulfill this dual need. The original two volumes – now available once more – are "An Introduction to the Electronic, Magnetic and Structural Properties" (Vol. I) and Measurement Techniques and Novel Magnetic Properties (this volume). Two new volumes, "Fundamentals of Nanomagnetism" and "Applications of Nanomagnetism," extend and complete this comprehensive work by presenting the foundations of spintronics.

Author: Dipti Ranjan Sahu
Publisher: BoD – Books on Demand
ISBN: 1839621605
Category : Science
Languages : en
Pages : 203

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Book Description
Magnetic materials are important materials for high-tech areas and technological development, which are being classified not only based on their origin but also by the nature of processing, properties, functions, and applications. This book presents an overview of the different types of new magnetic materials and hybrid structures that exhibit different magnetic phenomena and interesting properties. The reported materials are studied theoretically and experimentally, which are the building blocks of all technological innovations. Topics such as magnetic levitation are given for industrial applications. The chapters of the book provide a key description of magnetic materials. This book is suitable for undergraduate and graduate students and professionals including engineers, scientists, researchers, technicians, and technology managers. This book gives an idea to readers for scientific innovation in this field.

Author: J.A.C. Bland
Publisher: Springer Science & Business Media
ISBN: 9783540219538
Category : Technology & Engineering
Languages : en
Pages : 338

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Book Description
The ability to understand and control the unique properties of interfaces has created an entirely new field of magnetism which already has a profound impact in technology and is providing the basis for a revolution in electronics. The last decade has seen dramatic progress in the development of magnetic devices for information technology but also in the basic understanding of the physics of magnetic nanostructures. This volume describes thin film magnetic properties and methods for characterising thin film structure topics that underpin the present 'spintronics' revolution in which devices are based on combined magnetic materials and semiconductors. Volume IV deals with the fundamentals of spintronics: magnetoelectronic materials, spin injection and detection, micromagnetics and the development of magnetic random access memory based on GMR and tunnel junction devices. Together these books provide readers with a comprehensive account of an exciting and rapidly developing field. The treatment is designed to be accessible both to newcomers and to experts already working in this field who would like to get a better understanding of this very diversified area of research.

Author: Anthony Bland
Publisher: Springer Science & Business Media
ISBN: 9783540219552
Category : Science
Languages : en
Pages : 374

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Book Description
The ability to understand and control the unique properties of interfaces has created an entirely new field of magnetism which already has a profound impact in technology and is providing the basis for a revolution in electronics. The last decade has seen dramatic progress in the development of magnetic devices for information technology but also in the basic understanding of the physics of magnetic nanostructures. This volume describes thin film magnetic properties and methods for characterising thin film structure topics that underpin the present 'spintronics' revolution in which devices are based on combined magnetic materials and semiconductors. Volume IV deals with the fundamentals of spintronics: magnetoelectronic materials, spin injection and detection, micromagnetics and the development of magnetic random access memory based on GMR and tunnel junction devices. Together these books provide readers with a comprehensive account of an exciting and rapidly developing field. The treatment is designed to be accessible both to newcomers and to experts already working in this field who would like to get a better understanding of this very diversified area of research.

Author: David J. Sellmyer
Publisher: 清华大学出版社有限公司
ISBN: 9787302089247
Category : Magnetic materials
Languages : en
Pages : 484

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Author: Sam Zhang
Publisher: CRC Press
ISBN: 1315354349
Category : Science
Languages : en
Pages : 618

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Book Description
Advances in Magnetic Materials: Processing, Properties, and Performance discusses recent developments of magnetic materials, including fabrication, characterization and applications in the aerospace, biomedical, and semiconductors industries. With contributions by international professionals who possess broad and varied expertise, this volume encompasses both bulk materials and thin films and coatings for magnetic applications. A timely reference book that describes such things as ferromagnetism, nanomaterials, and Fe, ZnO, and Co-based materials, Advances in Magnetic Materials is an ideal text for students, researchers, and professionals working in materials science. Describes recent developments of magnetic materials, including fabrication, characterization, and applications Addresses a variety of industrial applications, such as aerospace, biomedical, and semiconductors Discusses bulk materials and thin films and coatings Covers ferromagnetism, nanomaterials, Fe, ZnO, and Co-based materials Contains the contributions of international professionals with broad and varied expertise Covers a holistic range of magnetic materials in various aspects of process, properties, and performance