Electronic and structural properties and phase transition of PbZr (1-0.5) Ti(0.5)O3: a computational study

• Grant number: 09/10701-0
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• Start date: April 15, 2010
• End date: May 14, 2010
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Julio Ricardo Sambrano
• Grantee: Julio Ricardo Sambrano
• Visiting researcher: Armando Beltrán Flors
• Visiting researcher institution: Universitat Jaume I , Spain
• Host Institution: Faculdade de Ciências (FC). Universidade Estadual Paulista (UNESP). Campus de Bauru. Bauru , SP, Brazil
• City of the host institution: Bauru

Abstract

The techniques of modeling and computer simulation applied to the solid state science have been more and more used in research and development of new materials. Theoretical and computational chemistry is turned back to shape structures and properties using the main principles of Physics and Chemistry of the Solid State, assisting the development of solar cells, capacitors, gas sensors, ferroelectric memories and many others devices. A class of materials that presents important and useful characteristics are ABO3 perovskites, where A and the B are modifier and former network elements. In particular, the class of the Titanates (PbZr(1 x)TixO3), a kind of combination that can vary in different percentages or concentrations of the maker elements, consists a class of materials with very important technological applications. Experimental studies indicate the possibility for the existence, when the atom concentration of Zr and PB is 50% (PbZr(1 0,5)Ti0,5O3), of three different crystallographic phases: monoclinic, tetragonal and cubic. This region of the phase diagram is especially interesting, due, mainly, of its places next to the morfotrópic contour of phase, a region where some of electric properties of this material are maximized. In this way, the objective of the present research project is to characterize from the theoretical and computational point of view the structural and electronic properties of PbZr0,5Ti0,5O3, in the monoclinic, tetragonal and cubic phases as well as the respective transitions' phase. We will apply the methodology, currently used in the scientific community, of periodic Density Functional Theory calculations. In this way, we hope to obtain relevant scientific contributions in the understanding of the different phases found in this material and open new possibilities to improve and/or innovate new possible technological applications. (AU)