Download or read book Structural Electronic and Magnetic Properties of Diluted Magnetic Semiconductors Based on Transition Metals Doped Zinc Oxide written by Bakhtiar Ul Haq and published by . This book was released on 2014 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Zinc Oxide based Diluted Magnetic Semiconductors written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: During my graduate research I have synthesized materials known as diluted magnetic semiconductors (DMS) as epitaxial thin film structures using the process of pulsed laser deposition (PLD). These materials are envisioned to be of importance in the emerging field of spintronics where the charge as well as the spin of the charge carriers can be combined to yield unique functionalities to yield novel devices including, on-chip memories, ultra-low power devices etc. The material of interest in this dissertation was zinc oxide, a wide bandgap optoelectronic semiconductor. ZnO has a bandgap of 3.3 eV. It is an ideal candidate for spintronics applications, because Zn is the last of the first row transition metals, which leads to pretty high solubility of transition metals such as Co, Mn and V in ZnO. In a diluted magnetic semiconductor a fraction of the host atoms is substituted by the transition metal dopant ion. We have found that we can synthesize very high quality, single phase and single crystalline Zn(TM)O thin films on basal plane sapphire single crystals (a-Al2O3). We have analyzed the magnetic properties of the three systems of ZnVO, ZnCoO and ZnMnO and found that ZnCoO and ZnMnO exhibit ferromagnetic ordering up to room temperature, when synthesized under high vacuum. In these conditions, the samples have a reasonable concentration of point defects which drive ZnO to n-type conductivity. By a combination of insitu and exsitu variation of parameters we have been able to tune the electronic and magnetic properties of these systems. From these studies we conclude that the main mechanism of magnetic ordering in these DMS materials is through a combination of defect related carrier induced exchange and bound magnetic polaron exchange. Device structures were fabricated using the as deposited samples to study the possibility of spin injection through semiconductors. We have observed that at low temperatures we see a considerable effect from this phenomenon in a m.
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 2018-10 with total page 177 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 Handbook of Zinc Oxide and Related Materials written by Zhe Chuan Feng and published by Taylor & Francis. This book was released on 2012-09-26 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: Through their application in energy-efficient and environmentally friendly devices, zinc oxide (ZnO) and related classes of wide gap semiconductors, including GaN and SiC, are revolutionizing numerous areas, from lighting, energy conversion, photovoltaics, and communications to biotechnology, imaging, and medicine. With an emphasis on engineering a
Download or read book Novel Diluted Magnetic Semiconductor Materials based on Zinc Oxide written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary aim of this work was to develop a ZnO based diluted magnetic semiconductor (DMS) materials system which displays ferromagnetism above room temperature and to understand the origin of long-range ferromagnetic ordering in these systems. Recent developments in the field of spintronics (spin based electronics) have led to an extensive search for materials in which semiconducting properties can be integrated with magnetic properties to realize the objective of successful fabrication of spin-based devices. For these devices we require a high efficiency of spin current injection at room temperature. Diluted magnetic semiconductors (DMS) can serve this role, but they should not only display room temperature ferromagnetism (RTFM) but also be capable of generating spin polarized carriers. Transition metal doped ZnO has proved to be a potential candidate as a DMS showing RTFM. The origin of ferromagnetic ordering in ZnO is still under debate. However, the presence of magnetic secondary phases, composition fluctuations and nanoclusters could also explain the observation of ferromagnetism in the DMS samples. This encouraged us to investigate Cu-doped(+ ư spin in the 2+ valence state) ZnO system as a probable candidate exhibiting RTFM because neither metallic Cu nor its oxides (Cu2O or CuO) are ferromagnetic. The role of defects and free carriers on the ferromagnetic ordering of Cu-doped ZnO thin films was studied to ascertain the origin of ferromagnetism in this system. A novel non-equilibrium Pulsed Laser Deposition technique has been used to grow high quality epitaxial thin films of Cu:ZnO and (Co, Cu):ZnO on c-plane Sapphire by domain matching epitxay. Both the systems showed ferromagnetic ordering above 300K but Cu ions showed a much stronger ferromagnetic ordering than Co, especially at low concentrations (1-2 %) of Cu where we realized near 100% polarization. But, the incorporation of Cu resulted in a 2-order of magnitude rise in the resistivity from 10-1 t.
Download or read book Zinc Oxide written by Hadis Morkoç and published by John Wiley & Sons. This book was released on 2008-12-03 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first systematic, authoritative and thorough treatment in one comprehensive volume presents the fundamentals and technologies of the topic, elucidating all aspects of ZnO materials and devices. Following an introduction, the authors look at the general properties of ZnO, as well as its growth, optical processes, doping and ZnO-based dilute magnetic semiconductors. Concluding sections treat bandgap engineering, processing and ZnO nanostructures and nanodevices. Of interest to device engineers, physicists, and semiconductor and solid state scientists in general.
Download or read book Diluted Magnetic Semiconductors written by Mukesh Kumar Jain and published by World Scientific. This book was released on 1991 with total page 682 pages. Available in PDF, EPUB and Kindle. Book excerpt: This review volume presents both basic and applied aspects of diluted magnetic semiconductors (DMS). The term DMS applies generally to semiconductors in which a fraction of its constituent ions are replaced by magnetic ions. This book is only the second to review DMS materials. It presents a detailed treatment of the current state of knowledge of the established properties of DMS in the form of single crystals, quantum wells and superlattices. It also brings together recent work on new DMS materials and presents discussions on a wide range of possible DMS applications.
Download or read book Structural and Magnetic Properties of Zno Doped with Mn and Co written by Vijay Kumar Sharma and published by LAP Lambert Academic Publishing. This book was released on 2010-12 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: ZnO based Diluted magnetic semiconductors (DMSs) have attracted broad interest for their promise functionalities in spintronics based devices. In this book, we explored the effect of different synthesis techniques (solid-state, sol-gel and chemical vapor deposition (CVD) methods) and synthesis parameters (sintering temperature, doping concentration, annealing atmosphere) on the structural and magnetic properties of TM (Mn, Co) doped ZnO. The effect of Al/Sb codoping on the magnetic properties of ZnMnO and ZnCoO were studied. We also explored the structural, optical and magnetic properties of nanowires and nanorods of Mn doped ZnO for their potential in spintronics based devices. From the experimental results presented in this book, it is concluded that defects like oxygen vacancies, zinc vacancies etc. in the samples are important for room temperature ferromagnetism in ZnO based DMSs.
Download or read book Diluted Magnetic Semiconductors written by Mukesh Jain and published by World Scientific. This book was released on 1991-10-31 with total page 677 pages. Available in PDF, EPUB and Kindle. Book excerpt: This review volume presents both basic and applied aspects of diluted magnetic semiconductors (DMS). The term DMS applies generally to semiconductors in which a fraction of its constituent ions are replaced by magnetic ions. This book is only the second to review DMS materials. It presents a detailed treatment of the current state of knowledge of the established properties of DMS in the form of single crystals, quantum wells and superlattices. It also brings together recent work on new DMS materials and presents discussions on a wide range of possible DMS applications.
Download or read book Nanomaterials Synthesis written by Yasir Beeran Pottathara and published by Elsevier. This book was released on 2019-05-29 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanomaterials Synthesis: Design, Fabrication and Applications combines the present and emerging trends of synthesis routes of nanomaterials with the incorporation of various technologies. The book covers the new trends and challenges in the synthesis and surface engineering of a wide range of nanomaterials, including emerging technologies used for their synthesis. Significant properties, safety and sustainability and environmental impacts of the synthesis routes are explored. This book is an important information source that will help materials scientists and engineers who want to learn more about how different classes of nanomaterials are designed. - Highlights recent developments in, and opportunities created by, new nanomaterials synthesis methods - Explains major synthesis techniques for different types of nanomaterials - Discusses the challenges of using a variety of synthesis methods
Download or read book ZnO Based Thin Films Nano Wires and Nano Belts for Photonic and Electronic Devices and Sensors written by Fan Ren and published by The Electrochemical Society. This book was released on 2008-10 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: The papers included in this issue of ECS Transactions were originally presented in the symposium ¿ZnO Based Thin Films, Nano-Wires, and Nano-Belts for Photonic and Electronic Devices and Sensors¿, during the PRiME 2008 meeting, held in Honolulu, Hawaii, from October 12 to 17, 2008.
Download or read book Nanowires written by Xihong Peng and published by BoD – Books on Demand. This book was released on 2012-12-19 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: One dimensional nanoscale structures such as nanowires have drawn extensive research interests in recent years. The size miniature brings unique properties to nanowires due to quantum confinement. The large surface-to-volume ratio renders nanowires with high sensitivity to surface effects. The unique geometrical advantages and properties facilitate the utilization of nanowires in nano-electronics. InTech scientific publisher has initialized a series of books focusing on fundamental research in nanowires, which largely boosted the widespread of knowledge among the research society. This book is intended to provide an updated review on the applications of various nanowires and the associated advancements in synthesis and properties characterization. The topics include recent progress in metal oxide nanowires, silicon nanowires, carbon based nanotubes and nanowires.
Download or read book ZnO Nanocrystals and Allied Materials written by M S Ramachandra Rao and published by Springer Science & Business Media. This book was released on 2013-09-12 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: ZnO has been the central theme of research in the past decade due to its various applications in band gap engineering, and textile and biomedical industries. In nanostructured form, it offers ample opportunities to realize tunable optical and optoelectronic properties and it was also termed as a potential material to realize room temperature ferromagnetism. This book presents 17 high-quality contributory chapters on ZnO related systems written by experts in this field. These chapters will help researchers to understand and explore the varied physical properties to envisage device applications of ZnO in thin film, heterostructure and nanostructure forms.
Download or read book Electromagnetic Materials and Devices written by Man-Gui Han and published by BoD – Books on Demand. This book was released on 2020-01-22 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electromagnetic materials can be widely found in daily life, especially in electronic devices. The high-frequency properties (permittivity or permeability) of these materials strongly depend on structure, composition, shape, and orientation. Therefore, this book intends to present readers with advances not only in materials science (including metamaterials), but also in measurements and novel functional applications that demand the special properties of electromagnetic materials.
Download or read book Magnetic Materials and Magnetic Levitation written by Dipti Ranjan Sahu and published by BoD – Books on Demand. This book was released on 2021-03-24 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Dilute Magnetic Semiconducting DMS Materials written by R. Saravanan and published by Materials Research Forum LLC. This book was released on 2018-08-25 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diluted Magnetic Semiconductors (DMS) play a vital role in modern electronics industry. It is important to understand the fundamental properties of these materials in order to apply them to their full potential. This book presents an analysis of the charge density distribution and other properties of some silicon and germanium based diluted magnetic semiconductors. A quantitative analysis of the charge density distribution has been done in order to obtain measurements of the charges involved in the bonding, which are decisive for the physical and chemical properties of the DMS materials. Also, the local structures of the materials have been analyzed by studying their powder X-ray diffraction intensities. Analysis of the magnetic properties of the DMS materials is mandatory and has been accomplished by magnetic measurements carried out using a vibrating sample magnetometer. The morphology of the DMS materials has been studied using scanning electron micrographs.
Download or read book Transition Metal Doped Zinc Oxide as Diluted Magnetic Semiconductor written by Zheng Zuo and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
