Effect of cation distribution on structural and mechanical properties of Y3+substituted Co-Zn spinel ferrites nanoparticles.

Abstract

Yttrium (Y3+) substituted Co-Zn spinel ferrite nanoparticles with compositional formula Co0.9Zn0.2YxFe1.9-xO4 (x = 0.0, 0.015, 0.030, 0.045, 0.06) were synthesized by using sol-gel auto-ignition route. The structural and mechanical properties of Co-Zn ferrites were tailored by the replacement of Fe3+ ions by Y3+ ions. Rietveld refined X-ray diffraction patterns of all the samples confirm the cubic spinel structure. Lattice parameter increases with the substitution of Y3+ ions which may be due to the difference in ionic radii. The crystallite size obtained from XRD analysis is found in the nanometer range of 16.8 - 24.7 nm. Distribution of cations over tetrahedral - A and octahedral - B sites have been studied by using X-ray diffraction data and it is found that Y3+ ions prefers the octahedral - B site. Infrared spectra of all the samples were recorded in the wave number range of 300 cm-1 to 800 cm-1 which shows splitting of the two fundamental absorption bands. Two absorption bands (ν1 and ν2) observed in the range 380 - 610 cm-1 are belongs to tetrahedral - A and octahedral - B interstitial sites. The force constants (KO and Kt) and corresponding elastic parameters were determined by using IR data. The stiffness constant (C11), Young's modulus (E), rigidity modulus (G), bulk modulus (B) and Debye temperature (θD) were found increases with the addition of Y3+ ions.