| Grant number: | 07/50968-0 |
| Support type: | Research Projects - Thematic Grants |
| Duration: | June 01, 2008 - May 31, 2014 |
| Field of knowledge: | Physical Sciences and Mathematics - Physics - Condensed Matter Physics |
| Principal Investigator: | Nei Fernandes de Oliveira Junior |
| Grantee: | Nei Fernandes de Oliveira Junior |
| Home Institution: | Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil |
| Co-Principal Investigators: | Gennady Gusev ; Pascoal Jose Giglio Pagliuso |
| Associated grant(s): | 12/08253-2 - 31st International Conference on the Physics of Semiconductors - ICPS 2012, AR.EXT |
| Associated scholarship(s): | 10/52628-5 - The electronic properties of graphite and graphene.,
BP.PD 08/04329-9 - Magnetic Nanostructures of Europium Telluride, BP.PD |
Abstract
The Laboratório de Estado Sólido e Baixas Temperaturas (LESBT) do IFUSP is the only one in Brazil with facilities for high magnetic fields, up to 20T, combined with low and very low temperatures, down to 0.01K. In this project, several research projects are proposed involving new materials, in which high fields and low temperatures are important. Two groups of new materials are involved: semiconducting nanostructures; and new magnetic materials. The projects involve III-V and IV-VI nanostructures produced by molecular beam epitaxy. Spintronics is the main motivation. In III-V systems, it is proposed: the study of AlxGa1-xAs parabolic quantum wells; transport studies of 2d electrons in AIGaAs/GaAs; studies on pseudo-spin quantum hall ferromagnetism, in double layer systems with anti-dot arrays. In the IV-VI group, the following is proposed: studies of carrier localization and anti-Iocalization in PbEuTe n and p thin films, and in Pb1-xEuxTe/Pb1-yEuyTe quantum wells; studies of magnetic interactions in EuTe/PbTe and EuTe/SnTe superlattices. It is proposed also studies in semiconductors of the III-Nitrides group, namely: cubic GaN epitaxial films, doped with magnetic and non-magnetic ions; -electric properties of the 2d electron gas the interface of cubic AIGaN/GaN heterojunctions; optical properties (including micro raman) of these systems; theoretical studies involving ab-initio methods of electronic structures and total energy calculations. In new magnetic materials, studies on four groups of new materials are proposed: new systems with strongly correlated electrons; manganites with colossal magneto¬ resistance; geometrically frustrated magnets; and organic magnetic materials. For the - first group it is proposed: preparation of single crystals of CeColn5-x(Sn,Ga)x, CeRh1-xlrxIn5 and CeRh1-xCoxln5 and related compounds to study heavy-fermions superconductivity, NFL(Non-Fermi Liquid) behavior and critical phenomena; study of a possible FFLO (Fulde-Ferrell-Larkin-Ovchinnikov) state in CeColn5-type compounds: and studies of fiel-induced magnetic transitions in Pr3Co4Sn13-type materials. For the second group it is proposed: the study of the critical behavior and time-dependent magnetization in materials such as La0.7-xYxCa0.3MnO3 and La0.62-XPrXCa0.38MnO3, as well as the study of some abrupt meta-magnetic transitions in mono and polycrystalline samples. In the third group it is proposed: magnetometric and specific heat studies in materials such as CdLn2Se4 (Ln = Dy, Ho) and CdLn2S4 (Ln = Ho, Er, Tm, Yb), and in ZnLn2S4 (Ln = Er, Tm, Yb). In the fourth group it is proposed magnetic interactions studies in a series of new organo-metalic and purely organic materials. Besides LESBT the following groups will be directly involved: the Laboratório de Novos Materiais Semicondutores (LNMS) do IFUSP, the Laboratório Associado de Sensores Materiais do Instituto Nacional de Pesquisas Espaciais (LAS-INPE) the Grupo de Propriedades Ópticas da Matéria (GPO) and the Grupo de Propriedades Óticas e Magnéticas dos Sólidos (GPOMS) both of the University of Campinas. Several national and international groups will also be involved. (AU)