X-ray absorption fine structure analysis of Mn1−xCoxFe2O4 nanoparticles prepared by hydrothermal method

Abstract

Mn1−xCoxFe2O4 nanoparticles (x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) were prepared by a hydrothermal method. The structure of samples was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and trans mission electron microscopy (TEM) and found to be an inverse spinel with a crystallite size in the range of 9–15 nm. The magnetic properties measured by vibration sample magnetometry (VSM) indicated that all samples were ferromagnetic with magnetization (M) at 10 kOe and coercivity in the ranges of 15–42 emu/g and 39–372 Oe, respectively. The oxidation states of Mn and Co cations in doped samples as analyzed by X-ray absorption fine structure (XANES) were found to be +3 and +2, respectively. Mn3+ and Co2+ cations were found at both tetrahedral and octahedral sites with a strong preference to be at the tetrahedral and octahedral sites, respectively. Fe2+ and Fe3+ cations were found to occupy both tetrahedral and octahedral sites with a higher stronger preference to be at the tetrahedral site.