The role of dysprosium levels in the formation of mixed oxidation states within spinel MnCo_2−xDy_xO₄ nanocrystalline powders

In this work, glycine-aided combustion synthesis of spinel-type MnCo_2−xDy_xO₄ (x = 0.02, 0.04 and 0.06 %) nanocrystalline powders is presented. The mechanism involved in the chemical synthesis is briefly discussed. The integrity of the synthesized nanocrystalline powders was investigated and evaluated in correlation with dysprosium levels. Powder X-ray diffraction and Fourier-transform infrared spectroscopy studies confirmed the formation of pure spinel phase with cubic crystal structure. Scanning electron microscopy examinations revealed different agglomerated porous spongy morphologies that varied with different dysprosium levels. The analyses of X-ray photoelectron spectroscopy spectra showed different mixed oxidation states and cationic distributions among the octahedral and tetrahedral sites within the spinel structure as a function of dysprosium levels. It is suggested that MnCo_2−xDy_xO₄ nanocrystalline powders with different morphologies and mixed oxidation states can be tailored via facile synthesis route.