AVS 49th International Symposium
    Magnetic Interfaces and Nanostructures Thursday Sessions
       Session MI+SS-ThM

Paper MI+SS-ThM2
MOKE Studies of Magnetic Coupling in Co/Cr@sub2@O@sub3@/CrO@sub2@

Thursday, November 7, 2002, 8:40 am, Room C-205

Session: Magnetic Spectroscopies
Presenter: R. Cheng, University of Nebraska-Lincoln
Authors: R. Cheng, University of Nebraska-Lincoln
A.N. Caruso, University of Nebraska-Lincoln
L. Yuan, University of Nebraska-Lincoln
S.-H. Liou, University of Nebraska-Lincoln
P.A. Dowben, University of Nebraska-Lincoln
Correspondent: Click to Email
CrO@sub 2@ is an attractive material for spin-polarized electron tunneling because of the high electron polarization and is among the predicted half metallic ferromagnets (metallic for one spin direction while insulating for the other spin direction, i.e. 100% spin polarization). Because the native surface layer of CrO@sub 2@ is Cr@sub 2@O@sub 3@, by evaporating Co thin films (5~20 nm) on top of epitaxial CrO@sub 2@ films on TiO@sub 2@ (100) substrates, a Co/Cr@sub 2@O@sub 3@/CrO@sub 2@ trilayer can be readily fabricated. >From in situ MOKE studies and ex situ SQUID measurements for the magnetic Co/Cr@sub 2@O@sub 3@/CrO@sub 2@ trilayers, the characteristic behavior of ferromagnetic-paramagnetic-ferromagnetic coupling above room temperature was observed. The thickness of Co and the temperature dependence of the magnetic hysteresis loops, obtained from MOKE, indicate different shapes, and the coercive fields show strong but not monotonic temperature dependence. These results indicate that there are changes in magnetic coupling and magnetization orientation particularly apparent as the temperature approaches the T@sub c@ of CrO@sub 2@.