Role of Cr3+ ions on superexchange coupling in α-Fe2O3 nanoparticles

• Published in: Physica. B, Condensed matter Condensed matter, 2012-07, Vol.407 (14), p.2716-2720
• Main Authors: Panda, N.R., Acharya, B.S., Nayak, P., Pati, S.P., Nath, B.K., Das, D.
• Format: Article
• Language: English
• Subjects: Chemical synthesis; Composite material; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic properties and materials; Magnetic properties of nanostructures; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Mossbauer spectroscopy; Mössbauer effect; other γ-ray spectroscopy; Physics; Super-exchange interaction; Transmission electron microscopy
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2012.03.071

Synthesis of nanocomposites of iron oxide & chromium oxide (α-Fe2O3–Cr2O3) with different concentrations was carried out by a wet-chemical method and the structural, optical and hyperfine properties have been investigated. The prepared nanocomposites were characterized by powder X-ray diffractometry (PXRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV–VIS spectroscopy, Fourier transformed infrared (FTIR) spectroscopy and Mössbauer spectroscopy. XRD measurements confirmed the formation of pure phase composites having particle sizes in nanometer regime. The same has been corroborated by TEM micrographs, which revealed that the formation of monodispersed nanocomposites have the average particle size 44nm. Mössbauer study of the samples showed the transition of iron oxide from anti-ferromagnetic state to paramagnetic state having a typical relaxation in the spectrum with increasing concentration of Cr2O3.