FePt nanoparticles protected by poly(N-vinyl-2-pyrrolidone) (PVP) as a protective agent are synthesized by a chemical route. Diameter dependence of coercivity at low temperatures below $20 K for the FePt nanoparticles synthesized at various reaction temperatures exhibits an anomalous magnetic behavi
Anomalous magnetic behavior of CuO nanoparticles
โ Scribed by Vijay Bisht; K.P. Rajeev; Sangam Banerjee
- Publisher
- Elsevier Science
- Year
- 2010
- Tongue
- English
- Weight
- 566 KB
- Volume
- 150
- Category
- Article
- ISSN
- 0038-1098
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โฆ Synopsis
We report studies on temperature, field and time dependence of magnetization on cupric oxide nanoparticles of sizes 9 nm, 13 nm and 16 nm. The nanoparticles show unusual features in comparison to other antiferromagnetic nanoparticle systems. The field cooled (FC) and zero field cooled (ZFC) magnetization curves bifurcate well above the Nรฉel temperature and the usual peak in the ZFC magnetization curve is absent. The system does not show any memory effects which is in sharp contrast to the usual behavior shown by other antiferromagnetic nanoparticles. It turns out that the non-equilibrium behavior of CuO nanoparticles is very strange and is neither superparamagnetic nor spin glass like.
๐ SIMILAR VOLUMES
In the present work, we study the deterministic spin dynamic of a two interacting magnetic particles, with both dipolar and exchange interactions in the presence of an applied magnetic field. Due to the strength ratio of interactions, two time scales appear; a longer one associated with the exchange