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Mostrando ítems 101-110 de 124
Investigação das fases formadas na superfície do aço inoxidável AISI 316L nitretado a plasma
(Universidade Federal de São Carlos, 2013-04-03)
The plasma nitriding treatment improves mechanical, tribological and corrosion resistance, due to the formation of a nitrided layer consisting of an iron and chromium nitrides and a phase, with an undefined structure, known ...
Magnetismo de nanofios de cobalto e níquel fabricados por eletrodeposição em alumina anódica porosa
(Universidade Federal de São Carlos, 2015-03-04)
In this thesis were investigated the magnetic properties of magnetic nanowire arrays of Co and Ni electrodeposited in porous anodic alumina templates. The electrochemical method was employed in the manufacturing steps of ...
Propriedades magnéticas de nanofios de cobalto autoformados por deposição à laser pulsado
(Universidade Federal de São Carlos, 2012-02-15)
Le sujet de cette thèse est l étude de nanofils de cobalt dans une matrice d oxyde de cérium (CeO2) épitaxiée sur SrTiO3(001). L auto-assemblage de nanofils a été mis en évidence lors de la croissance de couches minces de ...
Modelos dinâmicos de magnetização aplicados em compósitos magnetoelétricos
(Universidade Federal de São Carlos, 2014-04-01)
In this thesis we study the magnetic properties of the multiferroic composite (1-x)Pb(Mg1/3Nb2/3)-xPbTiO3/CoFe2O4 (PMN-PT/CFO) sintered by hot forging. Magnetization as a function of magnetic field, magnetoelectric effect ...
Modelos de spins geometricamente frustrados: transição de fase e estruturas de platores
(Universidade Federal de São Carlos, 2013-04-08)
This thesis presents a study of the magnetization plateau and the phenomenon of geometrical frustration in spin systems applied to lattices with triangular structure, as well as the results achieved by applying the ...
Efeitos de spin em diodos de tunelamento ressonante tipo-p
(Universidade Federal de São Carlos, 2012-03-27)
In this work, we have investigated the spin effects in p-i-p GaAs/AlAs resonant tunneling diodes under magnetic field parallel to the tunnel current. The spin-dependent tunneling of carriers was studied by analyzing the ...
Simulações de líquidos super-resfriados via dinâmica molecular
(Universidade Federal de São Carlos, 2012-10-15)
This work presents the study of two models of glass-forming liquids using molecular dynamics simulations. The first model aims to analyze the effects on glassy dynamics which allow the enhancement of the glass formability ...
Estrutura de platô na magnetização em modelos de spins frustrados
(Universidade Federal de São Carlos, 2012-10-26)
This thesis study the phase transition, forms classical and quantum models of spin frustration. The Heisenberg model of spin 1/2 with exchange anisotropy with competitive interactions between first (J1) and second (J2) ...
Estudo de primeiros princípios das propriedades eletrônicas de novos materiais derivados do grafeno : as nanofitas e nanofios
(Universidade Federal de São Carlos, 2012-09-05)
In this thesis, we study new materials derived from graphene, like nanowires and nanoribbons, with numerical calculations based on the density functional theory (DFT) and the non-equilibrium Green functions (NEGF). We will ...
Flux avalanches in patterned superconducting thin films: ac susceptibility, morphology and related studies
(Universidade Federal de São Carlos, 2013-04-12)
Avalanches are sudden dramatic phenomena that occur in nature. The technique of magneto-optical imaging (MOI) has allowed us to observe abrupt flux entrances in superconductors, the so-called ux avalanches, due to ...