Nanoparticles of Co in the structure of impregnated ZSM-5 zeolites

P. G. BERCOFF; H. R. BERTORELLO; C. SAUX; L. B. PIERELLA; T. KANAZAWA

Buenos Aires

Congreso; At the frontiers of Condensed Matter IV; 2008

We report the main results on the Co distribution over a ZSM-5zeolite (MFI struture) with $2.8$\% of cobalt ions incorporated bywet impregnation, as determined by using scanning electronmicroscope (SEM) in both secondary (SE) and transmission (STEM)modes and Energy Dispersive Spectroscopy (EDS). Each sizedistribution of Co particles originates a different contributionto the magnetization giving a ferromagnetic behavior in a widerange of temperatures, to which superparamagnetic contributionsfrom the smallest particles are superimposed.