Gas sensing properties of nanostructured Sm2O3 microspheres

M.A. PONCE, C.R. MICHEL, R. PARRA, Y C.M. ALDAO

Campos do Jordão

Congreso; XII Encontro da SBPMat; 2013

Samarium oxide (Sm2O3) displays notable catalytical behavior for the conversion of syn-gas to i-C4 hydrocarbons. However, few it is known about its electrical and gas sensing properties. In this work, nanostructured Sm2O3 microspheres were prepared by a co-precipitation method, using samarium nitrate and formic acid. The identification by XRD of a sample calcined at 600°C (in air), revealed the formation of single-phase Sm2O3. FESEM images show hollow spheres, with shells formed by Sm2O3 nanoparticles with size 70 nm. Electrical measurements of Sm2O3 films exposed to two different atmospheres (containing oxygen and CO) at 500 ºC showed an n-type semiconductor behavior and its possible use as a gas sensor. The electrical behavior was modelled using an RC parallel circuit representing the intergrains interface and a CPE representing the effect of deep traps.