Investigation of semiconductor oxide CeO2 doped with Fe and La by means of Perturbed Angular Gamma-Gamma Correlation Technique

Author(s)

Caio de Oliveira Salutte

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Pesquisas Energéticas e Nucleares (IPEN/BT)
• Defense date: 2013-12-18

Examining board members

Artur Wilson Carbonari; Jose Mestnik Filho; Emiliano Luis Munõz

• Advisor: Artur Wilson Carbonari

Abstract

Samples of cerium dioxide doped with La and Fe were fabricated and characterized by a technique based on nuclear hyperfine interactions known as Perturbed Angular Gamma-Gamma Correlation (PAC). As the used compound is not radioactive and the PAC technique requires a radioactive decaying through a cascade gamma-gamma, a radioactive probe nuclei were used (111In 111Cd - 171-245 keV), with intermediate has a half-life of 84ns, spin 5/2- and a moment of electric quadrupole Q= 0,83. Initially a methodology for the production of the samples had to be prepared. The cerium dioxide and its dopants were produced by the Sol-Gel process, undergoing a calcining and sintering. The sample are characterized by various types of techniques (X-ray Diffraction and Scanning Electron Microscopy) succeeding study through hyperfine Interactions, with the PAC technique, to an understanding of the electric quadrupole inteirações samples and also the possibility of the existence of magnetic behavior (subject intensively investigated given the interest in the field of spintronics). The results were analyzed taking the knowledge found in the literature and discussions were made on the basis of the variation of the doping element, thermal treatments used in the sintering temperatures and the different measures. Allowing a discussion and physical interpretation of results. (AU)

• FAPESP's process: 11/05408-2 - Preparation and characterization of nano-structured semiconductor oxide CeO2 samples doped with Fe, Mn and Ni by a nuclear investigation technique
• Grantee: Caio de Oliveira Salutte
• Support Opportunities: Scholarships in Brazil - Master