Magnetic properties of synthetic eumelanin--preliminary results.
We report an experimental and theoretical study of magnetic properties of synthetic eumelanin. The magnetization curves are determined by using both a vibrating sample magnetometer and a superconducting quantum interferometer device in an extended range of magnetic fields ranging from -10 kOe to 10 kOe at different temperatures. We find that the eumelanin magnetization can be qualitatively explained in terms of a simple model of dipolar spheres with an intrinsic magnetic moment. The latter one is experimentally measured by using X-band electron paramagnetic resonance. Our findings indicate that synthetic melanins are superparamagnetic.
Cano
M E
ME
Centro Universitario de la Ciénega, Universidad de Guadalajara, Ocotlán, Jalisco, Mexico.
Castañeda-Priego
R
R
Gil-Villegas
A
A
Sosa
M A
MA
Schio
P
P
de Oliveira
A J A
AJ
Chen
F
F
Baffa
O
O
Graeff
C F O
CF
D003198:Computer Simulation; D004578:Electron Spin Resonance Spectroscopy; D008280:Magnetics; D008543:Melanins / Q000138:chemical synthesis / Q000737:chemistry*; D009010:Monte Carlo Method; D013696:Temperature
D008543:Melanins; C041877:eumelanin