In-field 57Fe Mössbauer study of MgxZn1-xFe2O4 prepared by green synthesis method

This work reports honey green synthesis of MgxZn1-xFe2O4 (x = 0.0–1.0) spinel nano ferrite (grain diameter: 25.3 nm- 33.4 nm) by sol–gel auto-combustion method. Thermally treated samples at 550 °C for 3 h, were characterized by x-ray diffraction, ‘XRD’ scanning-electron-microscopy-energy-dispersive-x-ray-spectroscopy ‘SEM-EDS’, Mössbauer spectroscopy operating at 5 K with/without 5 T magnetic field. XRD confirms spinel phase formation, and presence of α-Fe2O3 (1.1–4.2%), while EDS confirms the uniform allocation of all the elements present in the studied samples. Agglomerated nano-particles are seen in SEM images. Increasing Mg-content: i) alters structural properties, ii) leads to modification of cationic population on A, B site, iii) affects A–O–A, B–O–B, A–O–B super-exchange interaction, and iv) shows linear decrease of Néel magnetic moment. Mössbauer results confirms 3+ state of Fe, and changes in local environment around Fe3+ ion induced modification of super-exchange interaction, reflected in internal hyperfine field. Finite canting angle suggests the applicability of Yafet-Kittel (Y-K) three sub-lattice model in describing magnetic behavior of the studied samples. Due to the presence of α-Fe2O3 in the studied samples, difference is observed in the inversion parameter, obtained from XRD, and Mössbauer data.