A (59)Co NMR study to observe the effects of ball milling on small ferromagnetic cobalt particles.
To demonstrate the potential of nuclear magnetic resonance (NMR) spectroscopy for investigating detailed structural properties in ferromagnetic materials, three different particle sized cobalt (Co) powders have been ball milled for 24h are accurately characterised by internal-field (59)Co NMR. The (59)Co NMR spectra show distinct resonance bands corresponding to the different Co sites, face-centred-cubic (fcc), hexagonal-close-packed (hcp) and stacking faults (sfs), in Co metal powders. The hcp+fcc-->hcp phase transition encouraged by ball-milling was observed and quantitative values for each Co environment were obtained.
Speight
R
R
Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK.
Wong
A
A
Ellis
P
P
Hyde
T
T
Bishop
P T
PT
Smith
M E
ME
D003036:Cobalt Isotopes / Q000032:analysis* / Q000737:chemistry*; D003198:Computer Simulation; D005240:Feasibility Studies; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008420:Manufactured Materials / Q000032:analysis*; D008422:Materials Testing / Q000379:methods; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D010316:Particle Size
D003036:Cobalt Isotopes