INVESTIGADORES
BOTTA pablo martin
artículos
Título:
Hyperfine and magnetic properties of a YxLa1 − xFeO3 series (0 ≤ x ≤ 1)
Autor/es:
A.A. CRISTÓBAL; P.M. BOTTA; P.G. BERCOFF; C.P RAMOS
Revista:
MATERIALS RESEARCH BULLETIN
Editorial:
PERGAMON-ELSEVIER SCIENCE LTD
Referencias:
Lugar: Amsterdam; Año: 2015 vol. 64 p. 347 - 354
ISSN:
0025-5408
Resumen:
A series of orthoferrites YxLa1 − xFeO3
in the entire range of composition was synthesized at room temperature
by mechanochemical activation of oxide mixtures. Phase composition,
structure and microstructure of the obtained powder materials were
characterized by X-ray diffraction and field-emission scanning electron
microscopy. Hyperfine interactions and magnetic properties were
determined by Mössbauer spectroscopy, SQUID and vibrating sample
magnetometry. Two magnetic contributions could be identified in the
series of materials: a paramagnetic state, associated with a fraction of
the smallest particles and a ferromagnetic state, attributed to the
larger particles. The results showed that the relative proportion of
both contributions is very dependent on x, the Y content of samples. From M vs T
measurements, it was possible to estimate the blocking temperature
distribution for the end members of the series. Annealing of samples
produced the elimination of the superparamagnetic behavior and the
formation of Y3Fe5O12 impurities.