Spectral Studies of the Ferrite System Zn0.5Cu0.5AlxFe2−xO4

TLDR: In this paper, the properties of Zn0.5Cu 0.5Al with respect to a paramagnetic phase C (quadrupole doublet ΔE) were analyzed using Mossbauer, X-ray and infrared spectra.

Abstract: Ferrite samples of Zn0.5Cu0.5Al x Fe2−x O4, 0≤x≤1 were studied using Mossbauer, X-ray and infrared spectra. Mossbauer spectra taken at room temperature show signs of relaxation for all samples. The obtained spectra were analysed into two Zeeman magnetic patterns assigned to the tetrahedral A- and octahedral B-sites and a paramagnetic phase C (quadrupole doublet ΔE). ΔE and the doublet area, which increase with x and the oxygen parameter u are studied. The quadrupole shift is small and may be ignored within experimental error. The isomer shift of the B-sites increases, with x while that of the A-sites does not change. The hyperfine magnetic field of the A-site (H A) is higher than that of the B-sites (H B). H B decreases for x≤0.8 and increases at x=1 while H A decreases for x≤0.4 and increases for x>0.4. This behaviour is discussed. The cation distribution has been estimated. The linewidth of the outermost A and B-sites and the calculated magnetization have been studied as functions of x for all samples. The B-sites show a composite pattern that has been successfully analysed into separate components. The obtained hyperfine parameters are discussed. The oxygen parameter, the ionic radius and the metal-oxygen bonds of the A- and B-sites were calculated for all samples. The infrared spectra show three vibration bands υ1, υ2 and υ4. The bands υ1 and υ2 show a shoulder, splitting and increasing overlap. Their behaviour has been discussed as a function of x. They show the same behaviour of magnetization and area ratio as the B- to A-sites. All parameters show a different behaviour at x=0.4, which is assigned to higher fraction of the Cu2+ ions in the A-site at this composition.