| Autor: |
Mukadam, M. D., Yusuf, S. M., Sasikala, R., Kulshreshtha, S. K. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 2/1/2006, Vol. 99 Issue 3, p034310, 6p, 1 Diagram, 4 Graphs |
| Abstrakt: |
Magnetic properties of Co2+-exchanged NaY zeolite have been investigated using a dc magnetization technique. In the presence of low applied magnetic fields, a difference between zero-field-cooled and field-cooled magnetizations is observed below ∼3.4 K. At T>5 K, the M vs H/T curves superimpose and these curves could be fitted well using the Langevin function, which yields a saturation moment of 3.2μB per Co2+ ion and a cluster moment of 6.66μB. This indicates that there are superparamagnetic clusters which are formed due to a positive exchange coupling among the Co2+ ions. For T<5 K, the M vs H/T curves do not superimpose on the curves for T>5 K. The analysis of the low-temperature M vs H data suggests the building up of weak antiferromagnetic-type correlation between the superparamagnetic clusters at T<5 K. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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