BIFUNCTIONAL MAGNETIC NANOPARTICLES SYSTEMS FOR GAMMA-DOSIMETRY

DINA TOBIA; ENIO LIMA JR; GUILLERMO FACCHINI; ROBERTO D. ZYSLER; MARIANA RANIERI; HORACIO E. TROIANI; ELIN WINKLER

Bariloche

Simposio; XXIII Latin American Symposium on Solid State Physics; 2018

Electron paramagnetic resonance (EPR) is a widely employed technique for non-destructive measurements of defect centers in organic materials caused byirradiation. In particular, L-Alanine (L-Ala) and Hydroxyapatite (HAp) are good based materials to employ in gamma-irradiation dosimetry. After ionizing radiation both systems exhibit defects that are stable in time and can be measured by EPR. The possibility of combining these materials with other phases that allow manipulation of different physical properties opens new fields for the design of specific sensors. For example, a bifunctional material can combine a magnetic phase, which allows the manipulation of the system through an external applied field, and a radiation sensitive phase that gives information of the received dose. With this objective we fabricated Fe3O4 and ZnxFe3-xO4 nanoparticles with diameters of 15-30 nm by the high-temperature decomposition method. Subsequently we combined the nanoparticles with the L-Ala or HAp phases through a simple wet chemical route. TEM micrographs confirmed the presence of magnetic nanoparticles embedded in the organic materials. The systems were gamma-irradiated at the RA-6 Nuclear Research Reactor located at the Centro Atómico Bariloche. Prior to irradiation, no L-Ala or HAp signals were detected by EPR. After irradiation, all systems exhibited the superimposed signals of both counterparts.