Magnetic polarization of Cu layers in exchange-coupled Co/Cu multilayers
Abstract
The magnetic polarization of delocalized Cu electrons in the layered Co/Cu structures and the exchange coupling energy of ferromagnetic Co moments across the Cu spacer have been calculated using the quantum-interference model. The quantum-well term of the total Cu spin moment oscillates versus the spacer thickness with a phase retarded by about π/2 from the coupling energy. This phase relation has been evidenced experimentally by measuring x-ray magnetic circular dichroic (XMCD) absorptions at the Co and Cu K edges from a series of Co/Cu multilayers with varying Cu thicknesses. The normalized Cu XMCD signals show a larger modulation as a function of Cu-layer thickness than predicted by the quantum-well term of the total Cu moment. The interface term makes marginal contributions to the total Cu moment probably because of the detrimental effects of rough interfaces in the sputter-deposited Co/Cu multilayers.
- Publication:
-
Physical Review B
- Pub Date:
- November 2006
- DOI:
- 10.1103/PhysRevB.74.174432
- Bibcode:
- 2006PhRvB..74q4432I
- Keywords:
-
- 75.30.Et;
- 87.64.Ni;
- 75.70.-i;
- 41.60.Ap;
- Exchange and superexchange interactions;
- Optical absorption magnetic circular dichroism and fluorescence spectroscopy;
- Magnetic properties of thin films surfaces and interfaces;
- Synchrotron radiation