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

Simposio; 20th Latin American Symposium on Solid State Physics -- SLAFES XX; 2011

PVA ferrogels were obtained through a one-pot technique that involves coprecipitationof iron salts in presence of a PVA solution, followed by freezingthawingcycles of the resulting NPs dispersions. The protecting effect of PVAenabled the synthesis of small magnetic nanoparticles (NPs) that did not agglomeratein the initial solution allowing the synthesis of well-dispersed ferrogelsby physical crosslinking. Magnetic properties of PVA ferrogels were measuredover the temperature range of 5k to 300 K. Coercitive field as functionof temperatures were obtained from the magnetization loops in the mentionedtemperature range. Fied Cooling-Zero Field Cooling measurement protocolwas performed with applied field of 50 Oe. Ferrogels showed superparamagneticproperties at room temperature and blocking temperature below 250K.