CETMIC   05378
CENTRO DE TECNOLOGIA DE RECURSOS MINERALES Y CERAMICA
Unidad Ejecutora - UE
artículos
Título:
Synthesis, structure and magnetic properties of distorted YxLa1-xFeO3: effects of mechanochemical activation and composition
Autor/es:
A. CRISTÓBAL; P. M. BOTTA; E. AGLIETTI; S. CONCONI; P. G. BERCOFF; J. M. PORTO LÓPEZ
Revista:
MATERIALS CHEMISTRY AND PHYSICS
Editorial:
ELSEVIER SCIENCE SA
Referencias:
Año: 2011 vol. 130 p. 1275 - 1279
ISSN:
0254-0584
Resumen:
The influence of mechanochemical treatment
on the synthesis and properties of YxLa1−xFeO3 (0 ≤ x ≤ 1)
orthoferrites is studied. Solid mixtures of the corresponding metal oxides were
treated in a high-energy ball-mill. X-ray diffraction revealed that during the
milling the disappearance of the reactants and a fast conversion to
orthoferrite phase take place. Magnetic measurements showed a weak
ferromagnetic behavior of the obtained materials, observing higher magnetization
for larger x. The activated powders heated at 600 and
800 ◦C
showed a progressive crystalline ordering together with a significant drop of magnetization.
Thermal treatments at 1000 ◦C produced the formation of the phase Y3Fe5O12 for the samples richer
in yttrium, increasing the magnetization. Rietveld refinements of the
diffraction patterns and dynamical scanning calorimetry were used respectively
to determine the lattice parameters and Néel temperatures for the formed
orthoferrites. The effect of the composition on the structure and magnetic behavior
is discussed.