Dynamic susceptibility investigation of maghemite nanoparticles incorporated in bovine serum albumin template.
Room-temperature measurements of the magnetic susceptibility of Bovine Serum Albumin-based nanocapsules (50 to 300 nm in size) loaded with different amounts of maghemite nanoparticles (7.6 nm average diameter) have been carried out in this study. The field (H) dependence of the imaginary peak susceptibility (fp) of the nanocomposite samples was investigated in the range of 0 to 4 kOe. From the analysis of the fp x H curves the concentration (N) dependence of the effective maghemite magnetocrystalline energy barrier (E) was obtained. Analysis of the E x N data was performed using a modified Mørup-Tronc [Phys. Rev. Lett. 72, 3278 (1994)] model, from which a huge contribution from the magnetocrystalline surface anisotropy was observed.
Universidade de Brasília, Instituto de Física, Núcleo de Física Aplicada, Brasília DF 70910-900, Brazil.
P C
PC
Morais
L B
LB
Silveira
A C
AC
Oliveira
B M
BM
Lacava
A C
AC
Tedesco
J G
JG
Santos
D005290:Ferric Compounds / Q000737:chemistry*; D008280:Magnetics; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles; D012710:Serum Albumin, Bovine / Q000737:chemistry*
D005290:Ferric Compounds; C000499:ferric oxide; D012710:Serum Albumin, Bovine