Development of Novel Magnetic Metal Oxide Films and Carbon Nanotube Materials for Magnetic Device Applications.

摘要

Earlier we reported the successful fabrication of out-of-plane exchange spring in sputter deposited CoFe2O4/CoFe2/CoFe2O4 structures. Synthesis of the 5 ferrimagnetic hard layer CoFe2O4 inoxygen-assisted environment contributed to the much larger coercive field in cobalt ferrite thin films. These results obtained in sputter-deposited CoFe2O4/CoFe2 samples are consistent with earlier work done on samples prepared with PLD (pulsed laser deposition). Recoil curves measurements done on samples with 10 improved coercive field showed much reduced energy loss indicating higher degree of exchange spring. As indicated by the normalized area of the recoil curve, a measure of the degree of exchange spring, we observe that our systems begin to nucleate before the field of irreversible switching, Hirr is reached. This suggests, especially for in-plane configuration,most of the moments of the soft magnetic layer are recovering their original 15 orientation. The decrease in the moment during recoil measurement can be reduced by introducing a preferred orientation for the moments in the soft magnetic layer.