Co nanoparticles inserted into a porous carbon amorphous matrix: The role of cooling field and temperature on the exchange bias effect
We report unusual cooling field dependence of the exchange bias in oxide-coated cobalt nanoparticles embedded within the nanopores of a carbon matrix. The size-distribution of the nanoparticles and the exchange bias coupling observed up to about 200 K between the Co-oxide shell (--3–4 nm) and the ferromagnetic Co-cores (--4–6 nm) are the key to understand the magnetic properties of this system. The estimated values of the effective anisotropy constant and saturation magnetization obtained from the fit of the zero-field cooling and field cooling magnetization vs. temperature curves agree quite well with those of the bulk fcc-Co.
Saved in:
| Main Authors: | , , , , , , , |
|---|---|
| Format: | artículo biblioteca |
| Language: | English |
| Published: |
Royal Society of Chemistry (UK)
2011
|
| Online Access: | http://hdl.handle.net/10261/52531 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | We report unusual cooling field dependence of the exchange bias in oxide-coated cobalt nanoparticles embedded within the nanopores of a carbon matrix. The size-distribution of the nanoparticles and the exchange bias coupling observed up to about 200 K between the Co-oxide shell (--3–4 nm) and the ferromagnetic Co-cores (--4–6 nm) are the key to understand the magnetic properties of this system. The estimated values of the effective anisotropy constant and saturation magnetization obtained from the fit of the zero-field cooling and field cooling magnetization vs. temperature curves agree quite well with those of the bulk fcc-Co. |
|---|