Structural and magnetic properties of nanocrystalline Bi1-xLaxFeO3 (0.0≤x≤0.4) synthesized by a mechanochemical route

• Published in: Materials research bulletin 2017-11, Vol.95, p.292-299
• Main Authors: Cristóbal, Adrián A., Ramos, Cinthia P., Conconi, M. Susana, Bercoff, Paula G., Botta, Pablo M.
• Format: Article
• Language: English
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2017.07.035

[Display omitted] •A mechanochemical reaction produces Bi1-xLaxFeO3 and NaCl in ambient conditions.•Heating at 600°C and ulterior washing yields ferrite phase for all the compositions.•The synthesized powders consist of agglomerates of Bi1-xLaxFeO3 nanoparticles.•La-content influences the crystal structure and Néel temperature of the materials.•The presence of two canting levels of antiparallel spins causes a complex magnetism. Bi1-xLaxFeO3 (0.0≤x≤0.4) powders were prepared by means of a solid acid-base reaction induced by mechanochemical energy. Bi, La and Fe chlorides were high-energy ball-milled with NaOH, yielding a mixture of Bi1-xLaxFeO3 and NaCl. After heating and washing, nanoparticles of Bi1-xLaxFeO3 were obtained as a main product, with low contents of secondary phases. Structural characterization was performed by X-ray diffraction (Rietveld refinement) and Raman spectroscopy. The hyperfine magnetic behavior was analyzed by means of Mössbauer spectroscopy and the microstructure of the particles was evaluated by transmission electron microscopy. Differential scanning calorimetry was employed to investigate the thermal behavior of the samples and magnetic measurements at room temperature were also carried out. Crystal structure transitions as a function of composition were identified. Moreover, an intricate magnetic behavior was observed, which was explained on the basis of the concomitant contribution of two different canting levels of the antiparallel spins.