Reversible switching of room temperature ferromagnetism in CeO2-Co nanoparticles

JOAQUIN SACANELL; MARIANO ANDRÉS PAULÍN; VALERIA FERRARI; GASTÓN GARBARINO; ANA GABRIELA LEYVA

APPLIED PHYSICS LETTERS

AMER INST PHYSICS

Año: 2012 vol. 100 p. 172405 - 172407

0003-6951

We investigated the reversible ferromagnetic (FM) behavior of pure and Co doped CeO2 nanopowders. The as-sintered samples displayed an increasing paramagnetic contribution upon Co doping. Room temperature FM is obtained simply by performing thermal treatments in vacuum at temperatures as low as 500ºC and it can be switched off by performing thermal treatments in oxidizing conditions. The FM contribution is enhanced as we increase the time of the thermal treatment in vacuum. Those systematic experiments establish a direct relation between ferromagnetism and oxygen vacancies and open a path for developing materials with tailored properties.