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Showing 1 to 20 of 20 for “"magnetic semiconductor"”.
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Diluted Magnetic Semiconductor Cobalt and Europium Implanted ZnO Thin Film
Diluted magnetic semiconductors (DMSs) have initiated enormous scientific interests because of their potential for multifunctional spintronics devices. ZnO based semiconductors have been identified to be the promising room temperature ferromagnetic materials with a wide band-gap. However, the …
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Diluted Magnetic Semiconductor Nanomaterials Fabrication by a Chemical Vapor Deposition Method
… ZnO lattice, resulting in room-temperature ferromagnetic coupling with a saturated magnetization of 0.25emu/g. The ferromagnetic interaction is weakened, however, by larger concentration of Mn, due to the antiferromagnetic coupling of direct superexchange interaction between Mn2+. The …
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Magnetic, thermodynamic and transport properties of the magnetic semiconductor Fe₁₋xCoxS₂ and superconducting LaSb₂
In recent years magnetic semiconductors have attracted a great deal of attention because it is thought that they can be used to generate spin polarized current in spintronics, an emerging field where the spin degree of freedom of charge carriers is utilized in microelectronic devices. In this …
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Optimization of gadolinium-doped zinc oxide films for diluted magnetic semiconductor and its effects on organic solar cell performance
Diluted Magnetic Semiconductors (DMS) are being actively studied as a major step towards the realization of spintronic devices. However, to obtain the DMS with ferromagnetic behaviour at room temperature is the main obstacle in the fabrication of spintronic devices. This obstacle has prompted …
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Transition metal implanted ZnO: a correlation between structure and magnetism
… is often found in potential diluted magnetic semiconductor systems. However, many authors question the origin of this ferromagnetism, i.e. if the observed ferromagnetism stems from ferromagnetic precipitates rather than from carriermediated magnetic coupling of ionic impurities, as …
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Disorder and Doping in the Oxygenated Electron-doped Superconductor PCCO
… the second part deals with the diluted magnetic semiconductor Ti_(1-x)Co_(x)O_(2-delta). It is not clear why oxygen reduction and cerium doping are necessary to obtain superconductivity in the electron-doped Pr_(2-x)Ce_(x)CuO_(4-delta). I investigated the effects of oxygenation in this …
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Synthesis and Characterization of Magnetic II-VI Nanoparticles
Magnetic semiconductor nanocrystals are being studied for their potential application in the field of spintronics as spin-injectors for spin-based transistors and spin-based storage elements for nonvolatile memories. They also have a number of biomedical engineering applications including contrast …
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Οπτικές ιδιότητες του αραιού μαγνητικού ημιαγωγού Ζn₁₋ₓΜnₓS
… Raman and luminescence study of the diluted magnetic semiconductor Ζn₁₋ₓΜnₓS has been carried out for concentrations x=0.03-0.5. The effects on the spectra of high-low temperature (T=20-1300K), hydrostatic pressure (p=0-5 GPa), and the excitation wavelength (λ=3507-6764 A) have been examined …
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MOVPE growth and characterization of Cr-doped GaN
… time with the intention of producing a dilute magnetic semiconductor (DMS) with room temperature ferromagnetism. To this end the following growth parameters were investigated and optimized: carrier gas, precursor access and ratios, and growth temperature as well as post growth annealing. Also …
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Many-body contributions to spin relaxation in semiconductors
… driven by the spin-orbit interaction in semiconductors, spin relaxation describes the rate at which spin polarized particles return to an equilibrium spin distribution. This is generally in competition with the goals of spintronic devices which generate out-of-equilibrium spin populations …
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Spin Currents in Organic Semiconductors
Organic semiconductors have recently been found to have a comparably large spin diffusion time and length. This makes them ideal candidates for spintronic devices. However, spin injection, transport and detection properties in organic materials have yet to be fully understood. This work studies …
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Zinc Oxide based Diluted Magnetic Semiconductors
… 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 …
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Spectroscopic study of emergent electronic phases in transition metal based compounds
… exhibit an inversion-symmetry-breaking antiferromagnetic order which directly induces ferroelectric polarization, allowing for symmetry protected cross-control between spin chirality and polar order. This intrinsic coupling between the magnetic and dipolar order parameters results in …
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Electrical control of spin dynamics in spin-orbit coupled ferromagnets
… for the development of efficient scalable magnetic memories. In materials with broken inversion symmetry and spin-orbit coupling, electrical current can exert a torque on a local magnetisation. In the studies presented here, a microwave current-induced ferromagnetic resonance (spin-orbit …
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The study of weak ferromagnetism by andreev reflection spin spectroscopy and development of bimorph electro-thermal actuators
… ferromagnet MnSi changes as it undergoes magnetic phase transition from helical to conical to induced ferromagnetic. Also, unconventional conductance with enhanced Andreev reflection with amplitude more than two, and conductance oscillations outside superconducting gap indicate the …
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Template-Controlled Synthesis of Magnetic/Semiconducting Nanoparticles within Amphiphilic Core-Shell Cylindrical Polymer Brushes
… of the polychelate containing Fe3+ ions. Magnetic nanoparticles were successfully produced from the coordinated iron cations within polymer brushes via single molecule templating technique, as confirmed by various techniques such as SFM, TEM, and UV/visible spectroscopy. Superconducting …
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Magneto-Optical Effects in Manganese-doped Lead Halide Perovskite
Magnetic doping holds a great potential for tailoring material properties of semiconductors via control over exciton-dopant interactions. Hybrid metal-halide perovskites are a new class of high-performance solution-processable semiconductors which combine remarkable optoelectronic performance with …
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Electronic properties of topological semimetal candidates ACd$_2$Pn$_2$ (A = Eu, Sr; Pn = As, Sb)
… the presence of Weyl points. Among them, ideal magnetic Weyl semimetals, characterized by a single pair of Weyl points close to the Fermi level, have long been sought for exploring the intrinsic topological effects associated with Weyl fermions free from interference by other trivial energy …
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Phase coherent transport phenomena in HgTe quantum well structures
… at least four to five times larger than in III-V semiconductors. Initially a short review on the transport theory was presented. The main focus as on quantisation effects that are important to understand the related experiments. Thus, Shubnikov-de Haas and the quantum Hall effect have been …
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Character of the electronic states near the metal-insulator transition in Gallium Manganese Arsenide
… metal-insulator transition in the ferromagnetic semiconductor Ga1-xMnxAs is studied by cross sectional scanning tunneling microscopy. 200nm thick samples grown by MBE at UCSB with doping levels from 1.5%, close the metal-insulator transition, to 5%, deep into the metallic regime, were …