Magnetic Frustration
Mostrando 1-6 de 6 artigos, teses e dissertações.
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1. Acoplamento spin-fonon em sistemas magneticamente frustrados / Spin-phonon coupling in magnetically frustrated systems
In this thesis we present an investigation of two magnetically frustrated systems, namely the RMn2O5 series (R = Eu, Bi, Dy) and the intermetallic compound GdAl3, in addition to the double perovskite compound Sr2CoUO 6. These systems were studied mainly using the Raman spectroscopy technique and complemented with magnetic susceptibility measurements. For the
Publicado em: 2007
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2. Reentrant spin glass behavior in polycrystalline La0.7Sr0.3Mn1-X FeX O 3
The magnetic and transport properties of the compound La0.7Sr0.3Mn1-xFe xO 3 (0.1 < x <0.4) have been studied by means of electrical resistivity, AC magnetic susceptibility, and DC magnetization. At low concentrations (x <0.1), the system displays essentially para-to-ferromagnetic transitions as the temperature is decreased, although a decrease in the magnet
Materials Research. Publicado em: 2004-06
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3. The Ising model and real magnetic materials
The factors that make certain magnetic materials behave similarly to corresponding Ising models are reviewed. Examples of extensively studied materials include Dy(C2H5SO4)3.9H2) (DyES), Dy3Al5O12 (DyAlG), DyPO4, Dy2Ti2O7, LiTbF4, K2CoF4, and Rb2CoF4. Various comparisons between theory and experiment for these materials are examined. The agreement is found to
Brazilian Journal of Physics. Publicado em: 2000-12
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4. Ba2LnSbO6 and Sr2LnSbO6 (Ln = Dy, Ho, Gd) double perovskites: Lanthanides in the geometrically frustrating fcc lattice
Magnetic ground states in solids often arise as a result of a delicate balance between competing factors. One currently active area of research in magnetic materials involves compounds in which long-range magnetic ordering at low temperatures is frustrated by the geometry of the crystalline lattice, a situation known as geometrical magnetic frustration.
National Academy of Sciences.
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5. Stochastic gene expression as a many-body problem
Gene expression has a stochastic component because of the single-molecule nature of the gene and the small number of copies of individual DNA-binding proteins in the cell. We show how the statistics of such systems can be mapped onto quantum many-body problems. The dynamics of a single gene switch resembles the spin-boson model of a two-site polaron or an el
The National Academy of Sciences.
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6. Correlation between lipid plane curvature and lipid chain order.
The 1-palmitoyl-2-oleoyl-phosphatidylethanolamine: 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPE:POPC) system has been investigated by measuring, in the inverted hexagonal (HII) phase, the intercylinder spacings (using x-ray diffraction) and orientational order of the acyl chains (using 2H nuclear magnetic resonance). The presence of 20 wt% dodecane leads t