Cation Distributions in Nickel Ferrites

Abstract

Crystal structures of magnetite ( Fe3O4) and Ni-ferrites ( Ni0.4Fe2.6O4 and Ni0.6Fe2.4O4) were determined using X-ray single-crystal diffraction methods. The single crystals were grown hydrothermally at 673–743 K, and some of the crystals were heated at 1303 K. After the positional and thermal parameters were initially determined using the MoKα radiation data set, the cation distributions were determined using the synchrotron radiation data set. The synchrotron X-rays were tuned at a wavelength 0.015 Å longer than the Fe K-absorption edge. This allowed us to precisely determine the cation distributions with a large difference in scattering factors. Our structural analyses with the synchrotron radiation measurements show that all the Ni ions in the ferrites are involved in the octahedral B sites.

Stainless steel/glass–ceramic interactions under hot isostatic pressing (HIPing) conditions

“…4(a)), the diffraction peaks are due to Fe 3 O 4 , Cr 2 O 3 , ferrite and the SS. Fe 3 O 4 forms a cubic phase with lattice parameter a = 0.8426 (6) nm which is about 0.3% larger than that reported earlier [7], probably because of substitution of impurities in the Fe 3 O 4 formed here.…”

Site-Specific Studies on X-Ray Magnetic Circular Dichroism at Fe K Edge for Transition-Metal Ferrites

“…This suggestion is in accordance with previous reports on the cation distributions in transition-metal ferrites, which are summarized in Table II. 7,8,19,[22][23][24][25] At the main edge, a positive peak of magnetite appears at E = 7.125 keV, while those of the other ferrites appear at E = 7.128 keV (Fig. 4).…”

A-site deficiency, phase purity and crystal structure in lanthanum strontium ferrite powders

“…The refinement parameters (lattice sizes and atomic positions) for SrFe 12 O 19 [27], SrLaFeO 4 [28], Fe 3 O 4 [29], and Sr 2 LaFe 3 O 8 [30] were fixed at values reported in literature.…”