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Preparation, Characterization of Components and MagneticProperties of Cd1-xEuxS Diluted Magnetic Semiconductor Nanoparticles

Author: QiuMingZe
Tutor: ZhangMing
School: Jilin University
Course: Condensed Matter Physics
Keywords: Cd1-xEuxS Diluted magnetic semiconductors Preparation Microwave Magnetic
CLC: TB383
Type: Master's thesis
Year: 2012
Downloads: 12
Quote: 0
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Abstract


Diluted magnetic semiconductors（DMSs）, also known as semi-magneticsemiconductors, doped with magnetic ions in the main material,such as Fe, Ni, Co, Mnand other elements.Those magnetic ions partially replace the main structure of the cation,and occupy the cation crystal princess point to be replaced the position of the formationof a semiconductor material.The magnetic ion substitution makes the diluted magneticsemiconductors with semiconductor properties, at the same time have good magneticproperties.Due to the special nature of the diluted magnetic semiconductor materials, theprospects of its application is quite broad.In recent years, people are increasinglyconcerned about the diluted magnetic semiconductor nanomaterials.There are many waysin the preparation of materials,such as sol-gel method, molecular beam epitaxy lowtemperature growth techniques, ion implantation technology, the reverse micelle method,pulsed laser deposition, sputter deposition, chemical vapor deposition and so on.While thehydrothermal synthesis method is the most common one.Hydrothermal synthesis is amethod of synthesis that chemical reaction conducted in aqueous solution at atemperature of1001000°C and the pressure of1MPa1GPa.In this paper,we use a novel synthesis method of self-designed to preparenanomaterials,which named gas-liquid surface reaction by microwave heating method.After the completion of the initial synthesis of the material gas-liquid surface reaction,microwave heating the reaction mixture was heated. The microwave heatingcharacteristics make the resulting material has a better properties.The main material weused is the CdS with wide band gap,and prepared the diluted magnetic semiconductornanoparticles Cd1-xEuxS doped with rare earth elements Eu ions. And after manyexperimental process,wefind the best conditions for synthesis.The prepared samples were detected by XRD, HRTEM, the XPS, EDS. The synthetic samples with different doping concentrations have roughly the same XRDpatterns.But with the doping concentration changes, the map of the diffraction peak hasobvious shift,and we can clearly see the structural changes in the high-resolution picture.After the analysis,we concluded that the distortion is on the main body of CdS （111）surface. We can be seen that the Eu elements exist in the main material by EDSdetection,and with the doping concentration increasing, the Eu content in the samples isincreasing.By XPS detection, we see the valence of the various elements, and thenconfirm that the Eu elements exist on the ion form but not non-metallic elemental form.In addition, we also conducted the magnetic measurement and testing about thesamples.and found that the sample has obvious ferromagnetic.We discussed thechacterization data on the composition and structure, concluded that Eu ions doped intothe host material Cds internal and there is no clusters formed by single quality of the Eumetal.It is concluded that the magnetic properties of the sample is shown because of thechange of its structure by doping. The magnetic properties of the sample showing a trendthat first increases and then decreases with the doping concentration increasing.

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