Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Development Of Transition Metal Doped Cu2o And Zno Dilute Magnetic Semiconductors
Download Development Of Transition Metal Doped Cu2o And Zno Dilute Magnetic Semiconductors full books in PDF, epub, and Kindle. Read online Development Of Transition Metal Doped Cu2o And Zno Dilute Magnetic Semiconductors ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Development of Transition-metal Doped Cu2O and ZnO Dilute Magnetic Semiconductors by : Mathew P. Ivill
Download or read book Development of Transition-metal Doped Cu2O and ZnO Dilute Magnetic Semiconductors written by Mathew P. Ivill and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Mn solubility in Cu2O was found to be small and the precipitation of Mn-oxides was favored at high growth temperatures. Phase pure Mn-doped Cu2O samples were found to be non-magnetic. Samples were p-type with carrier concentrations on the order of 1014-1016 cm−3.
Book Synopsis Transition Metal Doped Zinc Oxide as Diluted Magnetic Semiconductor by : Zheng Zuo
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 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transition metal doped ZnO has been proposed to be a Diluted Magnetic Semiconductor with room temperature ferromagnetism. High quality Mn doped ZnO was grown on R-sapphire substrate. Results support intrinsic ferromagnetism, while [Mu]B/ion number was found to be larger than maximum permitted by Hund's law. Saturation strength and coercivity field was found to be manipulated by varying Mn doping concentration. Mn/Ag co-doping was found to alter saturation strength and coercivity field as well. Ag was investigated as substitution dopant to achieve high quality p-type ZnO. With optimization of growth parameters, phase segregation was suppressed and p-type was observed. Besides being p-type, Ag doped ZnO was found to exhibit room temperature ferromagnetism. This is the first high quality demonstration of Ag doped ZnO as DMS.
Book Synopsis Novel Diluted Magnetic Semiconductor Materials based on Zinc Oxide by :
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.
Book Synopsis Study of Diluted Magnetic Semiconductors: the Case of Transition Metal Doped ZnO by : Zlatko Micković
Download or read book Study of Diluted Magnetic Semiconductors: the Case of Transition Metal Doped ZnO written by Zlatko Micković and published by . This book was released on 2010 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Study of Titanium Dioxide Based Dilute Magnetic Semiconductors by : Bakhtyar Ali
Download or read book Study of Titanium Dioxide Based Dilute Magnetic Semiconductors written by Bakhtyar Ali and published by ProQuest. This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Dilute magnetic semiconductors (DMSs) with high Curie temperature are highly desirable in spintronics applications. Transition metal doped oxides such as cobalt (Co), chromium (Cr), copper (Cu) doped TiO 2, ZnO, and SnO 2 are being studied for the last few years. Among other DMSs Co x Ti (1-x) O 2 anatase and rutile has been observed to have high T c (~400K). It is transparent in the visible and near infrared regions with a sizable band gap and appreciable conductivity. Therefore, it is believed to be very useful candidate for the fabrication of magnetic semiconductor devices. It has been shown that the achievement of magnetic percolation effect in DMSs is strongly linked to the nature of dopant and synthesis procedure which eventually leads to defects in the material. In this thesis we report the study of Co doped TiO 2 thin films and Cu:Co codoped TiO 2 nanopowders. Thin films of Co doped TiO 2 on silicon and quartz substrates are synthesized by pulsed laser deposition (PLD). Various oxygen partial pressures (P O2), ranging from 6.6 mPa to 53 Pa, are used to vary the oxygen content in the samples. Crystal structure and transport/ magnetic properties of Co x Ti 1-x O 2 (0.01 = x= 0.06) thin films are found to have a strong dependence on oxygen stoichiometry. X-ray diffraction (XRD) data reveal the presence of mixed phase material containing both anatase and rutile. However, the stability of each phase depends on the P O2 present in the chamber during the growth of the films. X-ray Photoelectron Spectroscopy (XPS) shows that Co is substituted in TiO 2 and is in the 2+ oxidation state. There is an enhancement in electrical conductivity and magnetization resulting from off stoichiometric (deficient) oxygen. The resistivity data fit well with the simple thermal activation model, giving activation energy values of 20 to 140 meV. In the second part we have studied the role of Cu codoping and oxygen vacancies in enhancing/stabilizing room temperature ferromagnetic interactions in Co doped TiO 2 nanopowder (cobalt being 5%, well bellow the cation percolation limit for TiO 2). Analyses of the XRD, TEM and XPS data reveal the cobalt incorporation into the lattice structure with no sign of phase segregations. The as-prepared paramagnetic Co-TiO 2 powder is rendered ferromagnetic by controlling the point defects (oxygen vacancies) in the sample. Interestingly, Cu codoping enhances the magnetization by an order of magnitude in the reduced Co doped TiO 2 . We believe that impurity band exchange mechanism is a plausible model in our Co-TiO 2 sample. The implication of the effect of Cu doping in Co doped sample is also discussed. We have also shown that the enhancement of ferromagnetism with additional doping in Co doped TiO 2 is a reversible effect.
Book Synopsis Defect-Induced Magnetism in Oxide Semiconductors by : Parmod Kumar
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
Book Synopsis Rare Earth and Transition Metal Doping of Semiconductor Materials by : Volkmar Dierolf
Download or read book Rare Earth and Transition Metal Doping of Semiconductor Materials written by Volkmar Dierolf and published by Woodhead Publishing. This book was released on 2016-01-23 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rare Earth and Transition Metal Doping of Semiconductor Material explores traditional semiconductor devices that are based on control of the electron’s electric charge. This book looks at the semiconductor materials used for spintronics applications, in particular focusing on wide band-gap semiconductors doped with transition metals and rare earths. These materials are of particular commercial interest because their spin can be controlled at room temperature, a clear opposition to the most previous research on Gallium Arsenide, which allowed for control of spins at supercold temperatures. Part One of the book explains the theory of magnetism in semiconductors, while Part Two covers the growth of semiconductors for spintronics. Finally, Part Three looks at the characterization and properties of semiconductors for spintronics, with Part Four exploring the devices and the future direction of spintronics. Examines materials which are of commercial interest for producing smaller, faster, and more power-efficient computers and other devices Analyzes the theory behind magnetism in semiconductors and the growth of semiconductors for spintronics Details the properties of semiconductors for spintronics
Book Synopsis Physical Properties of Dilute Magnetic Semiconducting Oxides by : Sudipta Bandyopadhyay
Download or read book Physical Properties of Dilute Magnetic Semiconducting Oxides written by Sudipta Bandyopadhyay and published by LAP Lambert Academic Publishing. This book was released on 2014-11-19 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transition metal doped ZnO has been studied from the perspective of its suitability in electronic applications. Bulk samples of Mn doped ZnO has been synthesized by solid state reaction and sol-gel techniques. Thin films of Mn doped ZnO has been synthesized by only sol-gel spin coating technique. So far as Co doped ZnO is concerned it is basically Co co-doped AZO [Al doped ZnO] film synthesized by sol-gel dip coating technique. Above 3 at% of Mn doping impurity phase has been developed for bulk powder sample. The impurity phase was completely or partially dissolved by ion beam irradiation. The role of Zn vacancy and substitutional replacement of Mn at Zn site is crucial for intrinsic ferromagnetism. Further counterbalancing antiferromagnetism and paramagnetism are also present. 2 at% Mn doped ZnO powder sample indicate metal insulator transition. Mn doped ZnO films exhibit defect induced ferromagnetism and interpreted in terms of bound magnetic polaron. Zn Vacancy favours and oxygen vacancy opposes intrinsic ferromagnetism in Mn doped ZnO film. Highly conducting Co co-doped AZO films shows potential for applications with interesting low temperature resistivity behaviour.
Book Synopsis The Effect of Nonmagnetic Doping and Growth Temperature on the Magneto-transport Properties of Mangenese [sic] and Cobalt Doped Zinc Oxide Dilute Magnetic Semiconductors by : Govind Mundada
Download or read book The Effect of Nonmagnetic Doping and Growth Temperature on the Magneto-transport Properties of Mangenese [sic] and Cobalt Doped Zinc Oxide Dilute Magnetic Semiconductors written by Govind Mundada and published by . This book was released on 2006 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis DEFECTS AND FERROMAGNETISM IN TRANSITION METAL DOPED ZINC OXIDE by : Sunil Thapa
Download or read book DEFECTS AND FERROMAGNETISM IN TRANSITION METAL DOPED ZINC OXIDE written by Sunil Thapa and published by . This book was released on 2016 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transition metal doped zinc oxide has been studied recently due to its potential application in spintronic devices. The magnetic semiconductor, often called Diluted Magnetic Semiconductors (DMS), has the ability to incorporate both charge and spin into a single formalism. Despite a large number of studies on ferromagnetism in ZnO based DMS and the realization of its room temperature ferromagnetism, there is still a debate about the origin of the ferromagnetism. In this work, the synthesis and characterization of transition metal doped zinc oxide have been carried out. The sol-gel method was used to synthesize thin films, and they were subsequently annealed in air. Characterization of doped zinc oxide films was carried out using the UV-visible range spectrometer, scanning electron microscopy, superconducting quantum interference device (SQUID), x-ray diffraction(XRD) and positron annihilation spectroscopy. Hysteresis loops were obtained for copper and manganese doped zinc oxide, but a reversed hysteresis loop was observed for 2% Al 3% Co doped zinc oxide. The reversed hysteresis loop has been explained using a two-layer model.
Book Synopsis Transition Metal Ions Doped Zno Nanopowders by : B. Babu
Download or read book Transition Metal Ions Doped Zno Nanopowders written by B. Babu and published by LAP Lambert Academic Publishing. This book was released on 2015-02-16 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Intensive research on semiconductor nanomaterials has increased remarkably during the past years due to their unique characteristics. Wide-band gap oxide semiconductors have occupied the forefront because of an increasing need for short wavelength photonic devices, high-power, high-frequency electronic devices. Doping with proper metal elements via introducing acceptor or donor in host material is an effective approach to tune the materials with requisite properties. Among different magnetic semiconductor materials, 3d transition metal doped ZnO has received maximum attention due to the observation of room temperature ferromagnetism with suitable magnetic dopant ions. Therefore, selection of proper doping element in ZnO has become an important route for enhancing and controlling electrical, optical and magnetic performances of nanomaterials. The objective of the present investigation is to synthesis, structural, spectroscopic and magnetic properties of transition metal ions doped ZnO nanopowders by solid state reaction with sonochemical assistance. The synthesized powders are characterized by XRD, SEM, Optical absorption, PL, FT-IR, EPR and VSM techniques.
Book Synopsis Transition Metal Doped ZnO for Spintronics by :
Download or read book Transition Metal Doped ZnO for Spintronics written by and published by . This book was released on 2007 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this project, the properties of transition metal (TM) -doped ZnO will be investigated. The project focuses on two activities. First, the properties of ZnO doped with transition metals (Mn, Co, or Cr) and deep level impurities (Cu, As, Sn) is explored. The primary interest will be on elucidating the origin of magnetism in the TM-doped material, including understanding the role of deep level co-dopants in mediating ferromagnetism. Experiments will focus on correlating magnetic properties (Curie temperature, moment/TM dopant) with the TM and deep level dopant concentrations. Epitaxial film growth and ion implantation of single crystals will be used in these studies. Second, for the dilute magnetic semiconducting compounds, there appears to be a correlation of Curie temperature with semiconductor bandgap. In an effort to increase the Curie temperature to greater than 300 K, the properties of TM-doped (Zn, Mg)O will also be investigated, as the addition of Mg to ZnO increases the bandgap. The epitaxial films will be grown by pulsed-laser deposition. Temperature-dependent Hall and resistivity measurements will be used to determine conduction mechanisms, carrier type, and doping. SQUID magnetometry will be used to characterize the magnetic properties of transition metal doped materials.
Book Synopsis Structure and Properties of 3d Transition Metal Doped ZnO by : Venkaiah Malapati
Download or read book Structure and Properties of 3d Transition Metal Doped ZnO written by Venkaiah Malapati and published by LAP Lambert Academic Publishing. This book was released on 2014-08-27 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: ZnO based semiconductors as transparent electrodes have given wide range of applications in optoelectronic devices due to their wide band gap replacing the conventional GaN semiconductors. This book is the compilation of the work of Venkaiah Malapati which deals with the synthesis and characterization of an interesting room temperature undoped and 3d transition metal doped ZnO thin films by rf magnetron sputtering. this work addresses the following three major questions... (1) what is the effect of working gas pressure on the properties of undoped and Mn, Fe and Mn-Fe co-doped ZnO thin films. Here, the effect of argon and oxygen gas pressure studied undoped and Mn and Fe doped thin films studied. This book includes a systematic study of structure, morphology, optical, mechanical and magnetic properties of undoped Mn, Fe doped ZnO thin films studied. This book should be useful to readers in enhancing their knowledge about thin film preparation and their characterization.
Book Synopsis First-Principle Vs Experimental Design of Diluted Magnetic Semiconductors by : Omar Mounkachi
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.
Book Synopsis Transition Metal Doped ZnO:Synthesis Structural and Optical Properties by : Sajid Husain
Download or read book Transition Metal Doped ZnO:Synthesis Structural and Optical Properties written by Sajid Husain and published by LAP Lambert Academic Publishing. This book was released on 2013 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book will provide a good understanding to readers about the chemical synthesis process of un-doped and doped ZnO nanoparticles. The various characterization has been done which emphasize to optoelectronic application on the basis of band gap tuning. And it has an immense application in DMS materials also. The additional information includes in the APPENDICES-A & B which might be useful for synthesis and the energy band gap calculation with theoretical reference.
Book Synopsis Diluted Magnetic Semiconductor ZnO by : Kuldeep Chand Verma
Download or read book Diluted Magnetic Semiconductor ZnO written by Kuldeep Chand Verma and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: For advancement in future spintronics, the diluted magnetic semiconductors (DMSs) might be understood for their origin of ferromagnetic aptness. It not much clear to the ferromagnetism in DMS, that is intrinsic or via dopant clustering formation. For this, we have included a review study for the doping of transition metal and rare earth ions in ZnO. It is realized that the antiferromagnetic ordering is found in doped ZnO to achieve high-TC ferromagnetism. X-ray diffraction and Raman spectra techniques have been used to detect the wurtzite ZnO structure and lattice defects. Since ZnO has different types of morphology formation that is generally dependent on synthesis conditions and dopant level. The band gap energy of ZnO and lattice defect formation are shown by photoluminescence technique. The room temperature ferromagnetism is described with bound magnetic polaron (BMP) model in which oxygen vacancies play a major role. However, the temperature-dependent conditions are responsible for ferromagnetic ordering. The first principle calculation is used for dopant ions in ZnO for their replacement of Zn2+ atoms in the wurtzite structure as well as magnetic contribution.
Book Synopsis Zinc Oxide based Diluted Magnetic Semiconductors by :
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 The Effect of Nonmagnetic Doping and Growth Temperature on the Magneto-transport Properties of Mangenese [sic] and Cobalt Doped Zinc Oxide Dilute Magnetic Semiconductors PDF Online Free](https://books.google.com/books/content/images/frontcover/iq6jtgAACAAJ?fife=w200-h370)
