Structural and 57Fe Mössbauer study of EuCr1 − x Fe x O3 nanocrystalline particles

Abstract

A structural and Mössbauer study of mechanosynthesized EuCr 1−x Fe x O 3 nanocrystalline particles (∼20-30 nm) is presented. The lattice parameters increase with increasing x-value leading to an increasingly distorted structure. The crystallite sizes range between 20 nm and 30 nm. Magnetic and 57 Fe Mössbauer measurements show the samples with x < 0.7 to be paramagnetic and those with x ≥ 0.7 to be partially superparamagnetic at 298 K. The 78 K Mössbauer spectra of the samples with x = 0.3-1.0 are composed of well-resolved two sextets that are explicable in terms of the structural model that we recently have proposed for the EuCrO 3 nanoparticles according to which the transition metal ions and Eu 3+ partly exchange their usual sites in the perovskite-related structure (Widatallah et al., J Phys D Appl Phys 44:265403, 2011). Consequently, the two sextets obtained at 78 K refer to Fe 3+ ions at the usual B-octahedral site and the A-dodecahedral site usually occupied by Eu 3+ .