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Showing 1 to 20 of 20 for “"Magnetic semiconductors"”.
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Ferromagnetism and transport in diluted magnetic semiconductors
… focuses on the study of ferromagnetism in Dilute Magnetic Semiconductors. To study these strongly correlated electronic systems, two non- perturbative techniques are used: the Dynamical Mean Field Approximation (DMFA) and the Dynamical Cluster Approximation (DCA). The model used for Dilute …
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Theory of photo-induced ferro-magnetism in dilute magnetic semiconductors
… study of photo-induced ferro-magnetism in dilute magnetic semiconductors. When light is incident on these systems, electrons and holes are created across the band gap. These particles interact with the impurity magnetic moments and mediate ferro-magnetism when temperature is lowered. This is a …
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Developing spectroscopic ellipsometry to study II-VI and diluted magnetic semiconductors
… ellipsometer (RAE) to study effects of magnetic and nonmagnetic doping on the £1 and £1 + .11 band gap energies in ZnSe-based II-VI semiconductors. To remove the natural surface oxide overlayer which distorts the intrinsic dielectric response of the sample, a chemical etching technique …
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New models of magnetic interactions for bound magnetic polarons in dilute magnetic semiconductors
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Physics, 1990
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Electrical gating effects on the magnetic properties of (Ga,Mn)As diluted magnetic semiconductors
… the effects of electrostatic gating on the magnetic properties of carrier-mediated ferromagnetic Ga1−xMnxAs diluted magnetic semiconductors. (Ga,Mn)As can be regarded as a prototype material because of its strong spin-orbit coupling and its crystalline properties which can be described …
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Understanding and Controlling the Magnetic and Optical Properties in van der Waals Semiconductors
… (2D) materials, 2D van der Waals (vdW) magnetic semiconductors are distinguished by their novel properties, which stem from the weak yet tunable interlayer magnetic interactions, adding an entirely new magnetic degree of freedom to vdW interfacial engineering. In this dissertation, we …
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Novel Quantum Materials for Spintronic and Opto-Electronic Applications
… instance, in spintronics, materials such as ferromagnetic half-metals, Giant Magnetoresistants (GMR), and magnetic semiconductors have been extensively studied due to their ability to manipulate the spin of electrons for applications in magnetic storage. In opto-electronics, materials such as …
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Current-induced torque driven ferromagnetic resonance in magnetic microstructures
… and an alternating current in a uniform ferromagnetic system. Diluted magnetic semiconductors (Ga,Mn)As and (Ga,Mn)(As,P) have been studied. Due to their strong spin-orbit coupling and well-understood band-structure, these materials are well-suited to this investigation. The combined effect of …
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Experimental validation of the predicted emergent magnetism in diamagnetic cadmium sulfide (Cds) doped with boron
… persistent photoconductivity displayed by some semiconductors provides a way to control magnetism with light, through illumination-control of free carrier concentration and thereby magnetic interaction in dilute magnetic semiconductors. CdS is a wide band-gap semiconductor that displays large …
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First-principles and Many-Body Methods: Implementations and Applications to Study Spintronic Materials
Diluted magnetic semiconductors (DMSs) and magnetoresistive materials are instrumental for the development of spintronic technology. Before we are able to engineer spintronic devices, it is necessary to understand the properties of materials from which spintronic devices are made, otherwise time …
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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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Nachweis der elektrischen Spin-Injektion in II-VI-Halbleiter mittels Messung des elektrischen Widerstandes
… verdünnte magnetische Halbleiter ("diluted magnetic semiconductors", DMS) als Injektor-Materialien für die elektrische Spininjektion in Halbleiter gut geeignet sind. Im Jahr 1999 wurde darüber hinaus die elektrische Injektion von einem DMS in einem nicht magnetisch dotierten Halbleiter ("non …
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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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Frustrated Magnetism in Strongly Correlated Electron Systems
… of magnetism is essential for its application in magnetic semiconductors, spintronic devices and unconventional superconductors. In this work, we study magnetic structures and their corresponding excitations in several strongly correlated electron systems, where exotic orderings can be induced as …
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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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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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Investigation of magnetic interactions in topological insulators
… This thesis is a comprehensive study of magnetic interactions in topological insulators, from both experimental and theoretical perspective. Generically, there are two approaches to bring TI magnetic, the proximity effect and the conventional transitional metal ion doping. In the …
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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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Spin and Carrier Relaxation Dynamics in InAsP Ternary Alloys, the Spin-orbit-split Hole Bands in Ferromagnetic InMnSb and InMnAs, and Reflectrometry Measurements of Valent Doped Barium Titanate
… alloys. The second project focused on the ferromagnetic narrow gap semiconductors InMnAs and InMnSb. The incorporation of Mn can lead to ferromagnetic behavior of InMnAs and InMnSb, and enhance the g-factors, making them ideal candidates for spintronics devices. When grown using Molecular Beam …
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ΜΕΛΕΤΗ ΜΑΓΝΗΤΟΑΝΤΙΣΤΑΣΗΣ ΣΕ ΜΟΝΟΚΡΥΣΤΑΛΛΟΥΣ FE7S8
… IS A STUDY OF THE MAGNETORESISTANCE IN ANTIFERROMAGNETIC SEMICONDUCTORS AND SPECIALLY IN PYRRHOTITE FE7S8 CUT FROM NATURAL SINGLE CRYSTALS (WITH ORIENTATIONS B C AND B// FROM 88 TO 607K. BEYOND THE NEEL POINT TN 600K AND FOR MAGNETIC FIELDS B FROM 0 TO 7 KG. A MAGNETORESISTANCE OF THE ORDER OF …