TY - JOUR
T1 - Effect of Nb in the nanocrystallization and magnetic properties of FeNbBCu amorphous alloys
AU - Torrens-Serra, J.
AU - Roth, S.
AU - Rodriguez-Viejo, J.
AU - Clavaguera-Mora, M. T.
PY - 2008/12/1
Y1 - 2008/12/1
N2 - The crystallization of melt-spun Fe79-xNb5+xB15Cu1 (x = 0, 2, 4) ribbons has been studied by differential scanning calorimetry and X-ray diffraction. A primary crystallization of bcc-Fe nanoparticles embedded in an amorphous matrix, followed by the precipitation of metastable borides from the residual matrix at higher temperatures is observed. The characteristic temperatures of crystallization events change with Nb concentration. The results obtained from thermal and structural characterization are related to the magnetic properties of the sample. A dependence of the magnetic behavior with the Fe/Nb content in the alloy is also unveiled. The decrease of Nb content in the alloy leads to an enhancement of both the saturation polarization and the Curie temperature due to variations in the exchange coupling between Fe atoms. However, the maximum values of magnetic entropy change do not vary appreciably among the three amorphous alloys. In nanocrystalline samples the amount of the nanocrystalline transformed fraction seems to be the main reason for the change in the saturation polarization of the sample. © 2008 Elsevier B.V. All rights reserved.
AB - The crystallization of melt-spun Fe79-xNb5+xB15Cu1 (x = 0, 2, 4) ribbons has been studied by differential scanning calorimetry and X-ray diffraction. A primary crystallization of bcc-Fe nanoparticles embedded in an amorphous matrix, followed by the precipitation of metastable borides from the residual matrix at higher temperatures is observed. The characteristic temperatures of crystallization events change with Nb concentration. The results obtained from thermal and structural characterization are related to the magnetic properties of the sample. A dependence of the magnetic behavior with the Fe/Nb content in the alloy is also unveiled. The decrease of Nb content in the alloy leads to an enhancement of both the saturation polarization and the Curie temperature due to variations in the exchange coupling between Fe atoms. However, the maximum values of magnetic entropy change do not vary appreciably among the three amorphous alloys. In nanocrystalline samples the amount of the nanocrystalline transformed fraction seems to be the main reason for the change in the saturation polarization of the sample. © 2008 Elsevier B.V. All rights reserved.
KW - Amorphous metals, metallic glasses
KW - Calorimetry
KW - Crystallization
KW - Magnetic properties
U2 - 10.1016/j.jnoncrysol.2008.05.057
DO - 10.1016/j.jnoncrysol.2008.05.057
M3 - Article
SN - 0022-3093
VL - 354
SP - 5110
EP - 5112
JO - Journal of Non-Crystalline Solids
JF - Journal of Non-Crystalline Solids
ER -