Synthesis, processing, and electron paramagnetic resonance response of Y1.98Eu0.02O3 micro rods

Author(s)

Santos, S. C. ; Rodrigues, O., Jr. ; Campos, L. L. ; Erickson, A ; Bernstein, A ; Hamm, M

• Document type: Journal article
• Source: PROCEEDINGS OF THE 7TH INTERNATIONAL WORKSHOP ON ASTRONOMY AND RELATIVISTIC ASTROPHYSICS (IWARA 2016); v. 48, p. 8-pg., 2018-01-01.

Abstract

Innovating dosimetric materials, which includes design and development of new dosimetric materials based on rare earth oxides, is challenging. Yttrium oxide (Y2O3) is one of the most important sesquioxides and presents crystal characteristics that enable doping with rare earth ions, making it a promising material for radiation dosimetry. This paper reports on the development and measurement of Electron Paramagnetic Resonance (EPR) signal response for Y1.98Eu0.02O3 micro rods that have undergone facile low-pressure hydrothermal synthesis and bio-prototyping. As-synthesized powders with narrow sub-micrometer particle size distribution with d(50) of 584 nm exhibited a reactive surface, which led to the formation of stable aqueous suspensions by controlling the surface charge density of particles through alkaline pH adjustment. Ceramic samples with dense microstructure were formed by sintering at 1600 degrees C for 4h at ambient atmosphere. Y1.98Eu0.02O3 micro rods were irradiated using a Co-60 source with doses from 1 to 100 kGy, and EPR spectra were measured at room temperature in X-band microwave frequencies. Sintered samples exhibited linearity of the main EPR signal response from 10 Gy to 10 kGy. Supralinearity was observed for higher doses, which is possibly ascribed to formation of more defects. Using europium as a dopant enhanced the EPR signal of yttrium rods remarkably, due to 4f-4f transitions of the Eu3+ ion. These innovative findings make europium-doped yttrium oxide a promising material for radiation dosimetry. (AU)

• FAPESP's process: 14/23621-3 - Development of ceramic materials based on rare earth doped yttria for application in radiation dosimetry
• Grantee: Silas Cardoso dos Santos
• Support Opportunities: Scholarships in Brazil - Post-Doctoral