Magnetic and structural changes in Cu1-xAlx alloy matrix - Embedded Fe nanoparticle systems
Abstract
We describe the atomic structure and magnetism in Fe nanoparticles (∼2 nm) ebedded in a Cu1-xAlx alloy matrix. Nanocomposite films for these studies were prepared directly from gas phase using a flexible co-deposition technique under Ultra-High Vacuum (UHV) conditions. Fe nanoparticles and the alloy matrix were prepared using a gas aggregation source and MBE sources respectively. Extended x-ray absorption fine structure (EXAFS) experiments indicate that the embedded Fe nanoparticles retain a bcc structure for Al-contents greater than x = 0.13 but, for Al-contents lower than this value, Fe nanoparticles have both fcc and bcc structures. The magnetic moment per Fe atom initially increases with increasing Al-content due to the bcc structure becoming more dominant in the embedded nanoparticles as the Al-content is increased, but then decreases with further increase in Al-content. This decrease is consistent with a modest degree of alloying between Fe and Al atoms at the particle/matrix interfaces.
- Publication:
-
Journal of Magnetism and Magnetic Materials
- Pub Date:
- February 2019
- DOI:
- 10.1016/j.jmmm.2018.08.040
- Bibcode:
- 2019JMMM..471..549K
- Keywords:
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- Fe nanoparticles;
- Magnetic;
- Atomic structure;
- EXAFS