Magnetic Semiconductors
Mostrando 25-34 de 34 artigos, teses e dissertações.
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25. "Spin and magnetic properties of the III-V group semiconductors" / "Propriedades magnéticas e de spin em semicondutores do grupo III-V"
We present the results of our investigations concerning MBE grown AlGaAs/GaAs parabolic quantum well (PQW) samples. We focused on the variation of the Landé g factor along the structure of the PQWs, which occur as a consquence of its dependence on the Al content on the alloy AlGaAs. The implications are studied by Hall and Shubnikov-de Haas measurements. Sh
Publicado em: 2006
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26. Éxcitons em semicondutores magnéticos diluídos / Excitons in diluted magnetic semiconductors
Investigamos o tunelamento ressonante de elétrons e buracos em um pouco quântico duplo assimétrico de CdTe/CdMnTe na presença de campos elétricos e magnéticos aplicados ao longo da direção de crescimento. Mostramos que neste caso é possível alcançar uma condição de tunelamento ressonante simultâneo de elétrons e buracos com spin definido, isto
Publicado em: 2006
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27. Manipulation with spin ordering in ferromagnetic semiconductors
A short overview is given of recent advances in the field of carrier-controlled ferromagnetism in Mn-based III-V and II-VI diluted magnetic semiconductors and their nanostructures. The tailoring of domain structures and magnetic anisotropy by strain engineering and confinement is described. Experiments demonstrating the tunability of T C by light and electri
Brazilian Journal of Physics. Publicado em: 2004-06
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28. Magnetic field induced absorption in Pb xEu1-xTe magnetic semiconductors
We report an investigation of the optical absorption spectrum, using non-polarized light, in Pb xEu1-xTe, x=0 and x=0.095, epitaxial thick layers grown by molecular beam epitaxy (MBE). The absorption edge is described by a broad band, due to the electronic transitions from the 4f7 of Eu2+ to the states in 4f6 5d configuration, as seen previously in bulk Eu c
Brazilian Journal of Physics. Publicado em: 2004-06
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29. STUDY OF THE STRUCTURAL AND MAGNETIC PROPERTIES OF Zn1-xMnxIn2Se4 SYSTEM / ESTUDO DAS PROPRIEDADES ESTRUTURAIS E MAGNÉTICAS DO SISTEMA Zn1-xMnxIn2Se4
This work reports a systematic study on the crystal growth and magnetic and structural properties of the diluted magnetic semiconductors (SMD) Zn1-xMnxIn2Se4. Crystals with Mn concentrations $0leqslant xleqslant 1.00$ were grown by chemical vapour transport (CVT). Through x-ray powder diffraction patterns and Laue diagrams of single crystal we studied the tr
Publicado em: 2004
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30. The 2D ion D- in the presence of a magnetic fied using adiabatic method hyperspherical / O íon D- bidimensional na presença de um campo magnético pelo método adiabático hiperesférico
The adiabatic hyperspherical approach (HAA) is used to determine the energies and wave functions of the bound states of a negatively charged ion (D-), in the presence of a magnetic field, in semiconductors. Experimentally, the bound energy of this system is measured with the ion confined in quantum wells, or either, the system is quasi-two dimensional, but,
Publicado em: 2002
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31. Celula de pressão biaxial e aplicações em filmes semicondutores
We had developed an apparatus, a biaxial pressure cell, which applies biaxial tensile strain in epitaxials semiconductor films. This system was customized to an immersion superconductor magneto-cryostat, which applies magnetic fields up to 15 T. It is a powerfull tool to the study the optical, magneto-optical and magneto-transport properties in the presence
Publicado em: 2002
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32. Estrutura eletrônica de heteroestruturas semicondutoras na presença de campos elétricos e magnéticos. / Electronic structure of semiconductor heterostructures in the presence of electric and magnetic fields.
Calculamos a estrutura eletrônica de heteroestruturas semicondutoras III-V e II-VI na aproximação da função envelope, usando o método k.p, na presença de campos elétricos e magnéticos externos. Para isso desenvolvemos um método numérico baseado na técnica das diferenças finitas e no método da potência inversa para resolvermos a equação de ma
Publicado em: 1999
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33. Estudo da influencia de lasers no aprisionamento de portadores, por impurezas em semicondutores submetidos a campos magneticos fortes
In this work the features of the screening of na ionized impurity is presented for semiconductors in the simultaneous presence of a laser field and a strong d.c. magnetic field at very low temperatures, taking into account these effects on the carriers freezeout in the ultra-quantum regime. It has been show specially that the carriers binding energy reduces
Publicado em: 1980
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34. The physics and chemistry of heavy fermions.
The heavy fermions are a subset of the f-electron intermetallic compounds straddling the magnetic/nonmagnetic boundary. Their low-temperature properties are characterized by an electronic energy scale of order 1-10 K. Among the low-temperature ground states observed in heavy fermion compounds are exotic superconductors and magnets, as well as unusual semicon