| Autor: |
Pankrats, A. I., Vorotynov, A. M., Tugarinov, V. I., Zharkov, S. M., Velikanov, D. A., Abramova, G. M., Zeer, G. M., Ramasamy, K., Gupta, A. |
| Předmět: |
|
| Zdroj: |
Journal of Applied Physics; 2014, Vol. 116 Issue 5, p054302-1-054302-8, 8p, 2 Black and White Photographs, 9 Graphs |
| Abstrakt: |
Nanoclusters and nanocrystals of the room temperature magnetic spinel CuCr2S4 synthesized using a facile solution-based method have been examined by transmission electron microscopy, magnetic measurements, and magnetic resonance over a wide frequency range 9.6-80 GHz and at temperatures down to 4.2 K. Decreasing of the resonance field and broadening of the resonance lines below 50K for both samples are due to the freezing of magnetic moments of nanocubes and nanocrystalline particles constituting nanoclusters. The effective fields of averaged magnetic anisotropy 〈HA〉≅ 2.4 kOe are similar for both nanopowder samples as estimated from resonance measurements at T=4.2 K. An additional blocking temperature Tb ≅ 300K appears in nanoclusters due to freezing of the magnetic moment of the entire cluster as a whole. Below this blocking temperature, the magnetic dipolar field acting in boundary areas of interacting constituent nanocrystals is responsible for the additional low-field resonance line observed in the resonance spectra of nanoclusters at X-band. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
