Study of organic and inorganic correlated systems

• Grant number: 13/16266-0
• Support type: Regular Research Grants
• Duration: November 01, 2013 - October 31, 2015
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Lygia Christina de Moura Walmsley
• Grantee: Lygia Christina de Moura Walmsley
• Home Institution: Instituto de Geociências e Ciências Exatas (IGCE). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil

Abstract

The goal of this project is to continue the study of transport and magnetic properties of organic and inorganic correlated systems. We want to advance the study of doped plasticized polyanilines, BiMn2O5 and start the study single crystals of Fe3O2BO3 and Ba0.96K0.04BiO3. In doped (protonated) plasticized polyanilines obtained from a collaboration with researchers of the CEA, Grenoble, our recent works evidenced the high degree of orientation of those free-standing films in electrical as well as magnetic properties, besides the identification of intrinsic weak ferromagnetism. In BiMn2O5 the systematic study of the synthesis conditions, thermal treatment and poling in the dielectric properties and Electron Spin Resonance (ESR) spectrum due to oxygen vacancies, will allow us to have a better understanding of the dielectric properties above the ferroelectric transition temperature (38K). In Fe3O2BO3 we are interested in the observation in the transport properties (resistivity, IxV and VxI curves) signatures of the transport due to the charge-density wave (CDW) condensate. This charge ordering has already been observed from Mössbauer spectroscopy and the dimerization observed from X-ray data. In single crystals of Ba0.96K0.04BiO3 that keeps the same monoclinic structure of BaBiO3 lattice distortions compatible with a charge ordering Bi3 - Bi5+, give rise to a CDW that opens a Peierls gap in the Fermi level. In this way, measurements of resistivity, dielectric constant and CDW characteristics, as well as comparison with the Fe3O2BO3 properties will be done in our study. Magnetic and ESR measurements will be performed in collaboration. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DOS SANTOS, E. C.; FREITAS, D. C.; FIER, I.; FERNANDES, J. C.; CONTINENTINO, M. A.; DE OLIVEIRA, A. J. A.; WALMSLEY, L. Current controlled negative differential resistance behavior in Co2FeO2BO3 and Fe3O2BO3 single crystals. JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, v. 90, p. 65-68, MAR 2016. Web of Science Citations: 2.