Download or read book ZnO based Diluted Magnetic Semiconductors for Applications in the Field of Spintronics written by Mariana-Mihaela Ungureanu and published by . This book was released on 2007 with total page 101 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 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 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 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 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.
Download or read book Spintronics Handbook Second Edition Spin Transport and Magnetism written by Evgeny Y. Tsymbal and published by CRC Press. This book was released on 2019-05-20 with total page 619 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second edition offers an update on the single most comprehensive survey of the two intertwined fields of spintronics and magnetism, covering the diverse array of materials and structures, including silicon, organic semiconductors, carbon nanotubes, graphene, and engineered nanostructures. It focuses on seminal pioneering work, together with the latest in cutting-edge advances, notably extended discussion of two-dimensional materials beyond graphene, topological insulators, skyrmions, and molecular spintronics. The main sections cover physical phenomena, spin-dependent tunneling, control of spin and magnetism in semiconductors, and spin-based applications.
Download or read book Effect of Strain Due to Substrates on Mn doped ZnO Dilute Magnetic Semiconductor Thin Films written by Srikanth Manchiraju and published by . This book was released on 2007 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 Zinc Oxide Based Diluted Magnetic Semiconductors written by Shivaraman Ramahandran and published by . This book was released on 2006 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: optoelectronics, spintronics, magneto-transport, thin films, magnetic, Diluted magnetic semiconductors, epitaxy, transmission electron microscopy, tunnel junction, magneto-resistance, spin injection.
Download or read book Nanomagnetism And Spintronics Fabrication Materials Characterization And Applications written by Farzad Nasirpouri and published by World Scientific. This book was released on 2010-12-21 with total page 401 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spintronics manipulates individual magnetic moments to integrate logic functions and non-volatile information storage on the same platform. As is often the case in condensed matter science, advances are made through the synthesis of novel materials and high quality new physics materials. Giant magnetoresistance and dilute magnetic semiconductors are two such examples. However, the remarkable potential of spintronics for quantum computation faces major challenges when it comes to controlling simultaneously several qbits encoded in magnetic moments.After a brief introduction to concepts in nanomagnetism and spintronics, the text reviews recent techniques and their achievements in the synthesis and fabrication of magnetic nanostructures. The methods presented here emphasize bottom up or top down approaches for nanodots, nanowires and thin films. They include: focused ion beam irradiation, electron beam-induced chemical vapour deposition, chemical, and electrochemical methods. The later part of the book reviews magnetoelectric materials, the giant magnetoresistance in magnetic superlattices, dynamics effects in spin transfer torque oscillators, dilute magnetic oxides, rare earth nitrides with nuclear resonance scattering, and Mössbauer spectroscopy in spintronics. Finally, the last part of this book discusses applications to magnetic storage and bio-magnetism.Nanomagnetism and Spintronics will be useful to graduate students and researchers and engineers in the field of nanoscience.
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 ZnO and Their Hybrid Nano Structures written by Gaurav Sharma and published by Materials Research Forum LLC. This book was released on 2023-06-05 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: ZnO and its hybrid nanostructures have unique optical, physical and chemical properties. The book covers recent trends in processing techniques and applications. Topics include solar cells, photo-voltaic devices, fuel cells, uv filters, lasers, light-emitting diodes, photo-detectors, spin-tronic devices, magnetic semiconductors, nano-generators, piezotronics, photo-catalytic applications against harmful organic pollutants like dyes, heavy metals, antibiotics, and sensors such as bio sensors, chemical sensors, gas sensors. Keywords: ZnO, Nano ZnO, Point Defects, Magnetic Semiconductors, Hybrid Nanostructures, Cell Applications, Nanoadsorbant for Heavy Metal Removals, Diagnostics, ZnO Nano-Carriers, ZnO Thin Films Fabrication.
Download or read book Novel Diluted Magnetic Semiconductor Materials Based on Zinc Oxide written by Deepayan Chakraborti and published by . This book was released on 2007 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: Cu doped ZnO, Thin Film Epitaxy, Structure-Property Correlation, Ferromagnetism, Spintronic, Magnetoresistance.
Download or read book Relationship Between Structure and Magnetic Behaviour in ZnO Based Systems written by Clara Guglieri Rodríguez and published by Springer. This book was released on 2015-06-03 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work studies the magnetic behavior of ZnO nanoparticles capped with different organic molecules and showing room-temperature ferromagnetism (RTFM). Of particular significance is the combination of element-specific X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) techniques, which demonstrates the intrinsic occurrence of RTFM in these systems and indicates that it is not related to the 3-D states of the metallic cation but is relayed along the conduction band of the semiconductor. The discovery of room-temperature ferromagnetism (RTFM) in semiconductors holds great promise in future spintronics technologies. Further results presented here include O K-edge XMCD studies, which demonstrate that the oxygen ions have a ferromagnetic response in these ZnO-based systems, providing the first direct support for claims regarding the appearance of oxygen ferromagnetism in oxide semiconductors at the nanoscale.
Download or read book Synthesis of Doped ZnO Based Bulk Dilute Magnetic Semiconductors and Their Nanophase Thin Films Using Pulsed Laser Ablation written by Shumaila Karamat and published by . This book was released on 2011 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:
