Exchange anisotropy in nanocasted Co3O4 nanowires.
Antiferromagnetic Co3O4 nanowires with an average diameter of about 8 nm have been synthesized by using the nanocasting route. The nanowires were characterized by powder X-ray diffraction, transmission electron microscopy, and a superconducting quantum interference device magnetometer. The magnetic measurements show a unidirectional exchange anisotropy accompanied by an enhancement of the field-cooled coercivity at low temperature. These effects suggest the presence of an exchange interaction between the antiferromagnetic core and the surface spins. A strong dependence of the exchange field on the magnitude of the cooling field and a training effect have been observed. The dependence of exchange bias field on temperature reveals the important role played by the antiferromagnetic core in the exchange coupling.
Salabaş
Elena Lorena
EL
Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany. salabas@mpi-muelheim.mpg.de
Rumplecker
Anja
A
Kleitz
Freddy
F
Radu
Florin
F
Schüth
Ferdi
F