MAGNETIC HYSTERESIS AND ROTATIONAL ENERGY BARRIERS IN C-COATED CO ANDRE TM FINE-PARTICLE FERROMAGNETS/

We use a Kratschmer-Huffman C-arc method to synthesize C-coated transi tion metal (TM) and rare earth (RE)-TM nanocrystals. The them of this research is C-arc synthesis of magnetic materials and assessment of po tential use in xerography, ferrofluids, data storage, MRI Image enhanc ement, etc, Here we focus on materials with potential for data storage . TM particles include Co[C]. Sm1-x-yCoXCy nanocrystals have been prod uced using a Sm2Co7 precursor, as have nanocrystalline Fe1-x-y-zNdXByC z using Fe14Nd2B. Characterization by XRD and HRTEM identify and phase s and particle sizes. SQUID magnetometry is used to determine magnetic hysteretis, temperature, and time dependent response.