|Support type:||Scholarships in Brazil - Post-Doctorate|
|Effective date (Start):||August 01, 2009|
|Effective date (End):||January 31, 2011|
|Field of knowledge:||Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry|
|Principal Investigator:||Marian Rosaly Davolos|
|Grantee:||Marco Aurélio Cebim|
|Home Institution:||Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil|
Scintillators are materials that can absorb high energy radiations as X-rays and gama-rays and can efficiently covert it to UV-visible light. Such materials are essential in medical imaging and high energy detection systems. The aim of this project is the study spectroscopic properties of core@shell-like particles using X-ray as an excitation source. Lanthanum oxide (La2O3) or lanthanum oxysulfide (La2O2S) will be prepared by the "poliol" method, followed by the sulfidization to reach the single oxysulfide phase. The particles will be recovered with a lutetium oxide (Lu2O3) shell, which posses a higher absorption of ionizing radiations than La2O3 or La2O2S. Furthermore, due to the Lu2O3 shell core@shell particles may suffer less radiation damage events than core-type particles. The resulting systems will be La2O3@Lu2O3 and La2O2S@Lu2O3, with a Pr3+- or Eu3+-doped core. The spectroscopy data will be compared in efficiency x life time diagrams, taking into account specific characteristics of the core@shell system, i. e., (1) variation of the core/shell diameter ratio: (a) a thinner shell than core, (b) comparable core and shell thickness, and (c) a thinner core than shell; and (2) variation of the refraction index from the core to the shell: (a) comparable core/shell reflection index , and (b) shell with higher refraction index than the core.