Physico-Chemical nanomaterials science

Time evolution of magnetic properties of MgFe2O4: Role of cation distribution
Raghuvanshi S.1, Tatarchuk T. R.2, Mazaleyrat F.3, Kane S. N.1
1 School of Physics, D. A. University, Khandwa Road, Indore-452001, India
2 Department of Chemistry, Vasyl Stefanyk Precarpathian National University, 57, Shevchenko Str., Ivano-Frankivsk, 76018, Ukraine
3 SATIE, ENS Universite Paris-Saclay, 61 Av. Pdt. Wilson, 94230, Cachan, France
E-mail of corresponding author: tatarchuk.tetyana@gmail.com

Fig. 1: Hysteresis loops Inset (a), (b) synthesis time dependent Hc,, Ms .

MgFe2O4 (MFO) is of particular interest for applications in biomedicine, magnetic technologies, heterogeneous catalysis etc. Existing literature on MFO reports correlation between structural and magnetic properties but, it does not reveal essential study on time evolution of structural, magnetic properties of these nano-ferrites. Such study will also fill the gap between laboratory researches and, the scale-up industrial production of nano-materials with desired properties, utilizing an energy efficient synthesis process (solution combustion method) with diminishing thermal costs while keeping the quality of materials. Present work reports synthesis time progression of structural, magnetic properties and antistructure modeling of MFO, to come-up with an optimized synthesis process exhibiting desired properties considered necessary for industrial applications. For the same, x-ray diffraction (XRD), vibrating sample magnetometer (VSM), field emission scanning microscopy (FE-SEM), energy dispersive spectroscopy (EDS) were used. XRD shows the formation of single phase nanocrystalline mixed cubic spinel structure (grain size 32.7–44.2 nm). Highest saturation magnetization (Ms) of 26.4 A·m2/kg, lowest coercivity (Hc) of 7769.4 A/m was obtained for the MFO sample collected after 30 minutes (see Fig. 1). Increasing synthesis time the observed reduction of Hc with simultaneous increase of Ms is of use for obtaining magnetically softer ferrites. Sample obtained at a lower synthesis time has higher specific surface area (S), and is more suitable for catalytic activity. Observed magnetic parameters are explained using cation distribution, surface dead layer. Antistructure modeling have been done to describe the concentration of active centers in tetrahedral (A) and octahedral (B) sites.