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Multiferroicity and structural anomalies in Quadruple Perovskite Manganites: case study (A)Mn7O12, A = Na and La
(Universidade Federal de São Carlos, 2019-01-15)
In this work we study the quadruple perovskite structure manganese oxides NaMn7O12 and LaMn7O12 under the point of view of multiferroicity, magnetoelectric coupling, and also structure anomalies on NaMn7O12. These studies ...
Influência do tamanho médio de grão nas propriedades ferroicas de compósitos magnetoelétricos particulados
(Universidade Federal de São Carlos, 2016-04-08)
In the case of composites materials, which presents the magnetoelectric coupling,
there are so many questions about the influence of the microstructure on the coupled
and uncoupled properties. Thereby, this work proposes ...
Efeitos da polarização elétrica sobre as propriedades magnéticas, térmicas e magnetoelétricas em compósitos multiferroicos de 0,675Pb(Mg1/3Nb2/3)O3-0,325PbTiO3/CoFe2O4
(Universidade Federal de São Carlos, 2018-12-10)
In this doctoral thesis, the magnetization, specific heat and magnetoelectric response (ME) measurements were carried out under remaining electric polarization conditions in the PMN-PT / CFO particulate multiferroic ...
Transport phenomena in quasi-one-dimensional heterostructures
(Universidade Federal de São Carlos, 2014-02-21)
O crescimento e caracterização de sistemas de heteroestruturas semicondutoras quasi-unidimensionais têm atraído grande interesse devido à sua potencial de aplicação tecnológica, como foto-detectores, dispositivos ...
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 ...
Avalanches de fluxo em filmes finos supercondutores estruturados : suscetibilidade ac, morfologia e outros estudos
(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 ...
Estudo sistemático das propriedades estruturais e magnéticas de amostras policristalinas do sistema PrxY1-xBa2Cu3O7-d
(Universidade Federal de São Carlos, 2008-08-10)
One of the most studied high TC superconductor is the YBa2Cu3O7 (Y-123) as well as the different substitutions on the Y site for different rare earth elements. Generally, this does not show important effects on the magnetic ...
Propriedades microestruturais e magnéticas de policristais de V2O5, CoV2O6 e Co3O4 sintetizadas por método Pechini
(Universidade Federal de São Carlos, 2014-11-27)
In this work we performed an extensive research about the magnetic properties of three materials, vanadium pentoxide (V2O5), cobalt tetraoxide (Co3O4) and cobalt vanadate II (CoV2O6). All the three oxides were synthesized ...
Dielectric and elastic response of perovskites: modelling and simulation
(Universidade Federal de São Carlos, 2013-09-09)
Nesta tese é estudada a resposta elástica e elétrica das perovskitas. As perovskitas são amplamente utilizadas em aplicações técnicas, sendo fundamental na eletrônica e no campo relativamente novo da nanoeletrônica. Elas ...
Manipulação de spin em diodos de tunelamento ressonante não-magnéticos tipo-n
(Universidade Federal de São Carlos, 2010-04-01)
The aim of this work was to study the spin effects in non-magnetic asymmetric n-type resonant tunneling diodes (RTD). For this purpose, we have used transport and polarization resolved magneto-photoluminescence measurement ...