Download or read book Investigaton of the Suitability of Wide Bandgap Dilute Magnetic Semiconductors for Spintronics written by Matthew Hartmann Kane and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: New semiconductor materials may enable next-generation 'spintronic' devices which exploit both the spin and charge of an electron for data processing, storage, and transfer. The realization of such devices would benefit greatly from room temperature ferromagnetic dilute magnetic semiconductors. Theoretical predictions have suggested that room temperature ferromagnetism may be possible in the wide bandgap semiconductors GaMnN and ZnMnO, though the existing models require input from the growth of high-quality materials. This work focuses on an experimental effort to develop high-quality materials in both of these wide bandgap materials systems. ZnMnO and ZnCoO single crystals have been grown by a modified melt growth technique. X-ray diffraction was used to examine the structural quality and demonstrate the single crystal character of these devices. Substitutional transition metal incorporation has been verified by optical transmission and electron paramagnetic resonance measurements. No indications of ferromagnetic hysteresis are observed from the bulk single crystal samples, and temperature dependent magnetization studies demonstrate a dominant antiferromagnetic exchange interaction. Efforts to introduce ferromagnetic ordering were only successful through processing techniques which significantly degraded the material quality. GaMnN thin films were grown by metalorganic chemical vapor deposition. Good crystalline quality and a consistent growth mode with Mn incorporation were verified by several independent characterization techniques. Substitutional incorporation of Mn on the Ga lattice site was confirmed by electron paramagnetic resonance. Mn acted as a deep acceptor in GaN. Nevertheless, ferromagnetic hysteresis was observed in the GaMnN films. The apparent strength of the magnetization correlated with the relative ratio of trivalent to divalent Mn. Valence state control through codoping with additional donors such as silicon was observed. Additional studies on GaFeN also showed a magnetic hysteresis. A comparison with implanted samples showed that the common origin to the apparent strong ferromagnetic hysteresis related to contribution from Mn substitutional ions. The observed magnetic hysteresis is due to the formation of Mn-rich regions during the growth process. This work demonstrated that the original intrinsic models for room temperature ferromagnetism in the wide bandgap semiconductors do not hold and the room temperature ferromagnetism in these materials results from extrinsic contributions.
Download or read book Growth of Novel Wide Bandgap Room Temperature Ferromagnetic Semiconductor for Spintronic Applications written by Shalini Gupta and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents the development of a GaN-based dilute magnetic semiconductor (DMS) by metal organic chemical vapor deposition (MOCVD) that is ferromagnetic at room temperature (RT), electrically conductive, and possesses magnetic properties that can be tuned by n- and p-doping. The transition metal series (TM: Cr, Mn, and Fe) along with the rare earth (RE) element, Gd, was investigated in this work as the magnetic ion source for the DMS. Single- phase and strain-free GaTMN films were obtained. Optical measurements revealed that Mn is a deep acceptor in GaN, while Hall measurements showed that these GaTMN films were semi-insulating, making carrier mediated exchange unlikely. Hysteresis curves were obtained for all the GaTMN films, and by analyzing the effect of n- and p-dopants on the magnetic properties of these films it was determined that the magnetization is due to magnetic clusters. These findings are supported by the investigation of the effect of TM dopants in GaN nanostructures which reveal that TMs enhance nucleation resulting in superparamagnetic nanostructures. Additionally, this work presents the first report on the development of GaGdN by MOCVD providing an alternate route to developing a RT DMS. Room temperature magnetization results revealed that the magnetization strength increases with Gd concentration and can be enhanced by n- and p-doping, with holes being more efficient at stabilizing the ferromagnetic signal. The GaGdN films obtained in this work are single-phase, unstrained, and conductive making them suitable for the development of multifunctional devices that integrate electrical, optical, and magnetic properties.
Download or read book Dilute Magnetic Semiconductors Based on Gan and Zno written by Tom Kammermeier and published by Sudwestdeutscher Verlag Fur Hochschulschriften AG. This book was released on 2010-05 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: The two wide band gap dilute magnetic semiconductors (DMS) Gd: GaN and Co: ZnO are among the most favored materials for spintronic applications. Despite intense research efforts during the last years, the origin of the magnetic order is still under debate. This work reports structural and magnetic investigations on these DMS materials employing several complementary techniques. The X-ray linear dichroism (XLD) has been used to gain element-specific insight into the local structure of dopants and cations. X-ray diffraction (XRD) has resulted in information about the global structural properties. Magnetic characterization by superconducting quantum interference device (SQUID) has been complemented by electron spin resonance (ESR) and X-ray magnetic circular dichroism (XMCD). This compilation of different techniques has yield new insight in the complex magnetic behavior of these wide band gap dilute magnetic semiconductor
Download or read book First Principle Vs Experimental Design of Diluted Magnetic Semiconductors written by Omar Mounkachi and published by Nova Science Publishers. This book was released on 2018 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent discoveries have given rise to a new class of electronics known as "spin electronics" or "spintronics," which uses the electron spin rather than its charge to create polarized currents. Spintronics is currently experiencing an extraordinary development with the manufacture of nanoscale devices based on ferromagnetic materials and semiconductors. Their applications are numerous, ranging from recording, electronics, and optoelectronics to quantum information. Spintronics is a new generation of electronics that has brought and continues to bring a lot of progress to information storage; this is due to the discovery of new materials with new functionalities and multiple applications. The discovery of giant magnetoresistance (GMR) in 1988 by Albert Fert and Peter Grünberg (receiver of the Nobel Prize in Physics in 2007) is considered a starting point of spintronics. GMR is based on the variation of the electric current in the presence of a magnetic field. The spintronics has made important contributions to the miniaturization desired for electronics; it uses nanometric components for processing and storing information. However, the limits of miniaturization on a nanometric scale are known, and it is imperative to develop new ways and new materials to exceed those limits. The most desired properties for these materials are high spin polarization, modular magnetic properties by an electric field and a long lifetime of the spin polarization. Among the new promising materials, we cite the following: Diluted magnetic semiconductors, which give new magnetic properties of conventional semiconductors, functional oxides (including the semi-metals and multiferroic metals) and organic semiconductors. The main theoretical challenge in this area is to understand how the macroscopic magnetic behavior observed results from interactions of a large number of degrees of microscopic freedom. In these systems the disorder is an essential parameter of magnetic phenomena, and due to random locations of impurity atoms it can lead to a total physical difference from the observed absence. There has been considerable recent advances in the design of these materials as diluted magnetic semiconductors (DMS, or diluted magnetic semiconductors), and a number of semiconductors were investigated as II-VI group and III-V group doped compounds, with transition metals substituting their original cations. There are several different theoretical approaches to study these magnetic materials. The ab-initio approach starts from the Schrödinger equation to simulate a given material. Such an approach is essential to determine the parameters and microscopic properties of such a system. In this book, the authors analyzed the electronic structure of magnetic semiconductors diluted in the case of ZnO, GaN, SnO2, TiO2, MgH2, EuO and EuN doped RENs (RE=GdN, DyN and HoN). The authors focused on magnetic, optical and exchange mechanisms which control the ferromagnetism in these systems. The purpose of this book is to propose some ideas to answer the most important question in material science for semiconductor spintronics, primarily considering how room-temperature ferromagnetism in DMS can be realized. Additionally, the correlation between first principle and experimental design to see how properties of yet-to-be-synthesized materials can be predicted is discussed.
Download or read book Europium Monoxide written by Arnold S. Borukhovich and published by Springer. This book was released on 2018-03-22 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the physical characteristics and possible device applications of europium monoxide as well as materials based on it. It reveals the suitability of this material for device applications in super- and semiconductor spin electronics. Ferromagnetic semiconductors like europium monoxide have contributed to a fascinating research field in condensed matter physics. In the book are presented the electronic and magnetic properties and thermal and resonance parameters of this material, its peculiarities in external fields as a function of non-stoichiometry, doping level, both in single-crystal and thin-film states. Particular attention is paid to the possibility to use this monoxide or its solid solutions (composites) unconventionally for creating spin electronics structures which work at room temperature conditions. This book appeals to researchers, graduate students and professionals engaged in the development of semiconductor spin electronics and computer devices, technologists and theoretical physicists. It is important for the calculation, development and creation of spin memory devices for a quantum computer.
Download or read book High temperature Ferromagnetism in Transition Metal Implanted Wide bandgap Semiconductors written by Jeremy A. Raley and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Spintronic Semiconductors written by Weimin Chen and published by CRC Press. This book was released on 2019-05-08 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an in-depth review of the rapidly developing field of spintronic semiconductors. It covers a broad range of topics, including growth and basic physical properties of diluted magnetic semiconductors based on II-VI, III-V and IV semiconductors, recent developments in theory and experimental techniques and potential device applications; its aim is to provide postgraduate students, researchers and engineers a comprehensive overview of our present knowledge and future perspectives of spintronic semiconductors.
Download or read book SISGR MuSR Investigations of Magnetic Semiconductors for Spintronics Applications written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structural and Magnetic Investigation of Dilute Magnetic Semiconductors Based on GaN and ZnO written by Tom Kammermeier and published by . This book was released on 2010 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dilute Magnetic Semiconductors for Spintronics written by Nana Pradhan and published by . This book was released on 2017-06-03 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Updates on Titanium Dioxide written by Bochra Bejaoui and published by BoD – Books on Demand. This book was released on 2023-08-30 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium dioxide (TiO2) has received a lot of attention due to its inexpensive cost, benign nature, and great photocatalytic potential. TiO2 has numerous applications, including in photocatalysts, Li-ion batteries, solar cells, and medical research. However, its performance is unsatisfactory due to a variety of issues, including a wide band gap (3.01 to 3.2 eV) and quick electron–hole pair recombination (1012 to 1011 s). Many efforts have been made to improve the qualities of TiO2, such as structural and dopant changes, which expand its applications. This book focuses on the properties of TiO2-modified nanoparticles, including their synthesis, alterations, and applications.
Download or read book Defect Induced Magnetism in Oxide Semiconductors written by Parmod Kumar and published by Elsevier. This book was released on 2023-05-26 with total page 738 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
Download or read book Materials Transactions JIM written by and published by . This book was released on 2007 with total page 1012 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spin Current written by Sadamichi Maekawa and published by Oxford University Press. This book was released on 2017 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a new branch of physics and technology, called spin-electronics or spintronics, the flow of electrical charge (usual current) as well as the flow of electron spin, the so-called "spin current", are manipulated and controlled together. This book is intended to provide an introduction and guide to the new physics and applications of spin current.
Download or read book Handbook of Spintronics written by Yongbing Xu and published by Springer. This book was released on 2015-10-14 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over two volumes and 1500 pages, the Handbook of Spintronics will cover all aspects of spintronics science and technology, including fundamental physics, materials properties and processing, established and emerging device technology and applications. Comprising 60 chapters from a large international team of leading researchers across academia and industry, the Handbook provides readers with an up-to-date and comprehensive review of this dynamic field of research. The opening chapters focus on the fundamental physical principles of spintronics in metals and semiconductors, including an introduction to spin quantum computing. Materials systems are then considered, with sections on metallic thin films and multilayers, magnetic tunnelling structures, hybrids, magnetic semiconductors and molecular spintronic materials. A separate section reviews the various characterisation methods appropriate to spintronics materials, including STM, spin-polarised photoemission, x-ray diffraction techniques and spin-polarised SEM. The third part of the Handbook contains chapters on the state of the art in device technology and applications, including spin valves, GMR and MTJ devices, MRAM technology, spin transistors and spin logic devices, spin torque devices, spin pumping and spin dynamics and other topics such as spin caloritronics. Each chapter considers the challenges faced by researchers in that area and contains some indications of the direction that future work in the field is likely to take. This reference work will be an essential and long-standing resource for the spintronics community.
Download or read book Diffusion and Defect Data written by and published by . This book was released on 2004 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nanostructured Metal Oxides and Devices written by M. K. Jayaraj and published by Springer Nature. This book was released on 2020-04-16 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book primarily covers the fundamental science, synthesis, characterization, optoelectronic properties, and applications of metal oxide nanomaterials. It discusses the basic aspects of synthetic procedures and fabrication technologies, explains the related experimental techniques and also elaborates on the current status of nanostructured oxide materials and related devices. Two major aspects of metal oxide nanostructures – their optical and electrical properties – are described in detail. The first five chapters focus on the optical characteristics of semiconducting materials, especially metal oxides at the nanoscale. The following five chapters discuss the electrical properties observed in metal oxide-based semiconductors and the status quo of device-level developments in a variety of applications such as sensors, transistors, dilute magnetic semiconductors, and dielectric materials. The basic science and mechanism behind the optoelectronic phenomena are explained in detail, to aid readers interested in the structure–property symbiosis in semiconducting nanomaterials. In short, the book offers a valuable reference guide for researchers and academics in the areas of material science and semiconductor technology, especially nanophotonics and electronics.
