AVS 51st International Symposium
    Magnetic Interfaces and Nanostructures Tuesday Sessions
       Session MI-TuM

Paper MI-TuM11
Magneto-Resistance in Epitaxial Nano-Contacts for Spintronic Device Applications

Tuesday, November 16, 2004, 11:40 am, Room 304A

Session: Spintronics
Presenter: D. Pearson, University of Toledo
Authors: D. Pearson, University of Toledo
R.A. Lukaszew, University of Toledo
Correspondent: Click to Email
Ballistic magnetoresistance (BMR) research has shown surprising MR effects in electrodeposited Ni nano-contacts at room temperature and low magnetic field@footnote 1@. A large BMR effect may arise from non-adiabatic spin scattering across very narrow (atomic scale) magnetic domain walls (DW) trapped at nano-contacts@footnote 2@. Kent el al@footnote 3@ have studied MR in epitaxial microstructures and found small intrinisc DW related effects only on highly anisotropic films. We have studied nano-contacts in various other epitaxial films. The idea behind our scheme is that epitaxial ferromagnetic thin films may favor non adiabatic spin transport provided that the nano-contact is small enough as predicted by Bruno. We used a similar geometry to that utilized by Chopra and Garcia@footnote 1@,@footnote 4@. The combined shape and magnetocrystalline anisotropies provide the required two states for the magnetization at each side of the constriction. Our results indicate that domain walls do play a role in the magnetoresistance of these nano-bridges. Micromagnetic simulations where carried out on the Ni nanocontacts using OOMMF. We will present our work on epitaxial Ni, FeN and CrO@sub 2@ nano-contacts. FeN exhibits enhanced magnetic moment and is an attractive candidate for write-heads. CrO@sub 2@ is a half metal with 100 percent polarization and therefore of fundamental interest in these studies. @FootnoteText@ @footnote 1@ S. Z. Hua and B. D. Chopra, Phys. Rev. B. 67, 060401(R), 2003.@footnote 2@ P. Bruno, Phys. Rev. Lett. 83, 2425 (1999).@footnote 3@ Kent, et al., J. Phys: Condens. Matter 13 (2001) R461.@footnote 4@ N. Garcia, M. Munioz, V. V. Osipov, E. V. Ponizovskaya, G. G. Quian, I.G. Saveliev and Y.-W. Zhao, J. Magn. Magn. Mater. 240, 92 (2002).