Estudo das propriedades ópticas e estruturais de nanocristais de MnTe em vidros óxidos

Abstract

Nanostructures based in Diluted Magnetic Semiconductors (DMS) - also referred as semimagnetic semiconductors have recently been attracting the interest of the scientific community due to its unique magneto-optical and transport properties. The possibility of manipulating single spins in DMS nanocrystals has recently been studied, making them an interesting physical problem with possible applications in the new field of spintronics. The nanostructures based on semiconductor compounds of the Pb1-xMnxTe, Ga1-xMnxTe and Cd1-xMnxTe type are particularly interesting. For a more accurate study of these compounds, for example, Cd1-xMnxTe an analysis of the magnetic and optical properties of CdTe and MnTe is indispensable. The CdTe is a non-magnetic binary system whose properties have been sufficiently analyzed and argued in literature. On the other hand, studies on the properties of the MnTe compound and its nanostructures are scarce or not satisfactorily detailed. The lack of information is particularly critical in the case of nanocrystals based in MnTe, owing to the difficulties in applying the techniques and in the growing process. This work report the first successfully growth of MnTe nanocrystals synthesized in a glass matrix SNAB (SiO2-Na2CO3-Al2O3-B2O3) using the fusion method. Measurements of Optical Absorption (AO), Photoluminescence (PL), Raman Spectroscopy (RE), Electronic Paramagnetic Resonance (EPR), Atomic Force Microscopy (AFM), X-ray Absorption Spectroscopy (XAS), and k.p method have been carried out in order to characterize the produced nanocrystals. The results put in evidence the formation of MnTe nanocrystals produced in glass matrix SNAB by fusion method.