Synthesis, characterization and magnetic behavior of Mg?Fe?Al mixed oxides based on layered double hydroxide

A. C. HEREDIA; M. I. OLIVA; AGÚ U.; C. I. ZANDALAZINI; S. G. MARCHETTI; E. HERRERO; M. E. CRIVELLO

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2013 vol. 342 p. 38 - 46

0304-8853

In the present work, Mg?Al?Fe layered double hydroxides were prepared by coprecipitation reaction with hydrothermal treatment. The characterization of precursors and their corresponding calcinated products (mixedoxides) were carried out by Xray diffraction, X-ray photoelectron spectroscopy (XPS), Termogravimetric Analysis and Differential Scanning Calorimetry, Diffuse Reflectance UV?vis spectroscopy, specific surface area, Mössbauaer and magnetic properties. The Fe3+ species were observed in tetrahedrally and octahedral coordination in brucite layered. The XPS analysis shows that the Fe3+ ions can be found in two coordination environments (tetrahedral and octahedral) as mixed oxides, and as spinel-structure. Oxides show a decrease in the specific surface areas when their on loading is increased. The magneticand Mössbauaer response show that MgAlFe mixed oxides are different behaviours such as different population ratios of ferromagnetic, weak-ferromagnetic, paramagnetic and superparamagnetic phases. The better crystallization of spinel structure with increased temperature, is correlated with the improved magnetic properties