Cobalt - poly(amido amine) superparamagnetic nanocomposites.
Metallic cobalt-dendrimer nanocomposites were prepared using generation 5 Poly(amido amine) dendrimers with primary amino termini. Cobalt loading of ~38 atoms per dendrimer was determined by atomic absorption spectrophotometry. Magnetic properties of the cobalt-dendrimer nanocomposites were investigated across the temperature range from 2-300 K by SQUID magnetometry. Magnetization as a function of temperature and applied field strength was studied in zero field cooled samples. Magnetization-demagnetization curves (hysteresis loops) were also acquired at temperatures between 10 - 300 K. These results clearly indicate superparamagnetism for the nanocomposites with a characteristic blocking temperature of ~50 K.
Atwater
James E
JE
UMPQUA Research Company, 125 Volunteer Way - P.O. Box 609, Myrtle Creek, Oregon 97457, USA.
Akse
James R
JR
Holtsnider
John T
JT