Magnetic Properties of PVA Ferrogels obtained through a One-pot Freezing-Thawing Procedure

DIEGO MURACA; P M ZELIS; K SHARMA; R K PIROTA; JIMENA GONZALEZ; CRISTINA HOPPE; VERA ALEJANDRA ALVAREZ; FRANCISCO SANCHEZ

Maragogi

Conferencia; 20th Latin American Symposium on Solid State Physics; 2011

PVA ferrogels were obtained through a one-pot technique that involves coprecipitation of iron salts in presence of a PVA solution, followed by freezingthawing cycles of the resulting NPs dispersions. The protecting effect of PVA enabled the synthesis of small magnetic nanoparticles (NPs) that did not agglomerate in the initial solution allowing the synthesis of well-dispersed ferrogels by physical crosslinking. Magnetic properties of PVA ferrogels were measured over the temperature range of 5k to 300 K. Coercitive field as function of temperatures were obtained from the magnetization loops in the mentioned temperature range. Fied Cooling-Zero Field Cooling measurement protocol was performed with applied field of 50 Oe. Ferrogels showed superparamagnetic properties at room temperature and blocking temperature below 250 K.