IFEG   20353
INSTITUTO DE FISICA ENRIQUE GAVIOLA
Unidad Ejecutora - UE
artículos
Título:
Sr hexaferrite/Ni ferrite nanocomposites: magnetic behavior and microwave absorbing properties in the X-band
Autor/es:
S. E. JACOBO; P. G. BERCOFF; C. A. HERME; L. A. VIVES
Revista:
MATERIALS CHEMISTRY AND PHYSICS
Editorial:
ELSEVIER SCIENCE SA
Referencias:
Lugar: Amsterdam; Año: 2015 vol. 157 p. 124 - 129
ISSN:
0254-0584
Resumen:
Nickel ferrite nanoparticles were synthesized by a self-combustion method over nanocrystalline powders of Nd-Co substituted strontium hexaferrite with nominal composition Sr0.5Nd0.5Co0.5Fe10.5O19, at different mass relations. The samples were structurally characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDX). The M vs. H loops of the composites were determined with a vibrating sample magnetometer (VSM) and the interaction with the X-band microwave radiation of the nanocomposites dispersed in epoxy resin was measured with a vector network analyzer (VNA). The hysteresis loops showed strong exchange-coupling between the two magnetic phases for the 30:70 and 50:50 Sr0.5Co0.5Nd0.5Fe10.5O19/NiFe2O4nanocomposites, while a weak interaction was observed for the 70:30 mass ratio. The nanocomposite with an equal amount of hard and soft phase shows the highest performance both in reflectivity and in bandwidth, reaching a maximum in reflectivity of 34.4 dB at 11.1 GHz while the bandwidth below 10 dB is 3.5 GHz.