journal article·2004-03-18

From Hollow to Dense Spheres: Control of Dipolar Interactions by Tailoring the Architecture in Colloidal Aggregates of Superparamagnetic Iron Oxide Nanocrystals

P. Tartaj, T. González‐Carreño, C. J. Serna

Advanced Materials· Volume 16· Issue 6
Publisher page

Abstract

The synthesis of spherical colloidal aggregates (see Figure) of superparamagnetic iron oxide nanocrystals with different packing fractions is reported. Using a mean‐field model, the magnitude of dipolar interactions between nanomagnets has been correlated with differences in their assembly. The results could help understanding of the magnetic behavior of magnetic liposomes and hollow capsules, which are promising for drug delivery.
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Research context

OpenAlex topics: Characterization and Applications of Magnetic Nanoparticles

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References (30)

Show source-provided references
1. 10.1002/1521-4095(20021016)14:20<1499::AID-ADMA1499>3.0.CO;2-510.1002/1521-4095(20021016)14:20<1499::AID-ADMA1499>3.0.CO;2-5 ↗
2. 10.1002/anie.20025044310.1002/anie.200250443 ↗
3. Niemeyer C. · Angew. Chem. Int. Ed. · 2001 · 40 · 128
4. 10.1021/ja027470910.1021/ja0274709 ↗
5. 10.1021/ja038059410.1021/ja0380594 ↗
6. 10.1103/PhysRevLett.80.18110.1103/PhysRevLett.80.181 ↗
7. 10.1021/jp026089810.1021/jp0260898 ↗
8. 10.1021/jp027314o10.1021/jp027314o ↗
9. 10.1038/nature0170210.1038/nature01702 ↗
10. 10.1103/PhysRevB.64.14442010.1103/PhysRevB.64.144420 ↗
11. 10.1088/0022-3727/36/13/20210.1088/0022-3727/36/13/202 ↗
12. 10.1088/0022-3727/36/13/20110.1088/0022-3727/36/13/201 ↗
13. 10.1002/anie.20039035210.1002/anie.200390352 ↗
14. 10.1021/ja021223n10.1021/ja021223n ↗
15. 10.1021/ja028850x10.1021/ja028850x ↗
16. 10.1002/1521-4095(200110)13:20<1579::AID-ADMA1579>3.0.CO;2-G10.1002/1521-4095(200110)13:20<1579::AID-ADMA1579>3.0.CO;2-G ↗
17. 10.1021/la025566a10.1021/la025566a ↗
18. 10.1002/1521-4095(200111)13:21<1620::AID-ADMA1620>3.0.CO;2-Z10.1002/1521-4095(200111)13:21<1620::AID-ADMA1620>3.0.CO;2-Z ↗
19. 10.1063/1.36709310.1063/1.367093 ↗
20. Evidence of hollowness in the samples was corroborated by scanning electron microscopy. Using this technique we observed a similar microstructure in all samples. In the scanning mode we only observed the surface of particles and since the resolution is much smaller than in the transmission mode we can expect dense and hollow spheres to appear similar.
21. 10.1016/0304-8853(92)90272-P10.1016/0304-8853(92)90272-P ↗
22. 10.1103/PhysRevB.52.28710.1103/PhysRevB.52.287 ↗
23. 10.1103/PhysRevB.66.18441310.1103/PhysRevB.66.184413 ↗
24. C. Kittel Introduction to Solid State Physics Wiley New York1968.
25. 10.1016/0304-8853(83)90407-910.1016/0304-8853(83)90407-9 ↗
26. 10.1002/cphc.20030086610.1002/cphc.200300866 ↗
27. According to Equation 2 the parameterT* depends not only on α andNbut also onMS. BecauseMSdepends on temperature we can expect differences in the value ofT* at different temperatures. This is the reason why we estimateT* at 300 K (working temperature for most of the relevant technological applications of magnetic nanoparticles).
28. A fit with Equation 3 superimposed with a log–normal particle size distribution results in strongly correlated parameters ofT* and the median particle size. However the agreement between the particle size estimated following this model and that estimated from X‐ray diffraction seems to suggest that the fit was reliable. In any case it is clear that the mean field model is successful in describing dipolar interactions between nanomagnets.
29. 10.1016/S0304-8853(00)01235-X10.1016/S0304-8853(00)01235-X ↗
30. 10.1016/S0304-8853(00)01228-210.1016/S0304-8853(00)01228-2 ↗