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Rare earth ions as structural probes: investigation of rare-earth ions influence on doping in spinel Zn7Sb2O12

Grant number: 06/06978-9
Support type:Scholarships in Brazil - Scientific Initiation
Effective date (Start): March 01, 2007
Effective date (End): December 31, 2009
Field of knowledge:Physical Sciences and Mathematics - Chemistry
Principal Investigator:Ana Maria Pires
Grantee:Andreza Cristina Souza Silva
Home Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil

Abstract

Rare earth ions (RE) include the lanthanide elements and also scandium and yttrium, and are extensively used in luminescent material compositions which are applied in image devices, fluorescent lamps as well. The several applications of rare earth elements are due to their optical and magnetic properties, in particular the Eu3+, which allow their use as structural probes. When semiconductor solid matrices are doped with rare earth ions luminescent emission can take place. The colour nature of lanthanides and actinides are originated from f-f transitions, and the luminescence is a consequence of internal 4f electronic transitions shielded by 5s and 5p electrons. Many semiconductors already show transitions among internal electronic levels, such as the spinel type (AB2O4) oxide system which can present magnetic, electrical, catalytic and sensor properties. Ceramics based in Zn7Sb2O12 reverse spinel type prepared from modified Pechini method, for instance, have been studied in particular due to their electrical features as temperature sensors. Therefore, the aim of this work is the doping of Zn7Sb2O12 semiconductor with rare earth ions, in special Pr3+ and Eu3+ ones. In the case of Eu3+, beyond its potentiality as luminescent material, this will be used as a probe in order to perform structural elucidation as well as the investigation of the influence of this ion in the structural and electrical features of this semiconductor.