Magnetic properties of Cu_xCo_1-xFe_2-xAl_xO₄oxides

Abstract

We report the magnetic properties of CuxCo1-xFe2-xAlxO4 with x values ranging from 0 to 1.0 in steps of 0.1. The samples were characterized by x-ray diffraction, Mössbauer spectroscopy and magnetization measurements. All samples crystallized with single-phase cubic spinel structure. Lattice parameter decreases with x according to Vergad's law. The Mössbauer spectra show the presence of magnetic hyperfine fields for x ≤ 0.9 due to Fe3+ ions on the tetrahedral (A) and octahedral (B) sites. The hyperfine magnetic fields decrease with increasing x. The variations of coercive fields and saturation magnetization with increasing Cu and Al concentrations observed are discussed.