A modification of the buoyancy method for characterizing and determining porosity in nanoporous magnesium ferrite samples.

Abstract Nanoporous materials with their characteristic electrical, magnetic and catalytic properties have shown great potential for industrial applications. A subset of such materials, porous metal oxides has been of great interest due to wide-ranging industrial applications, enabled by their porous morphology which allow for favourable electrical conductivity and large surface area. Therefore, it has been of significant importance to determine the morphology of such materials and investigate the nature and extent of its porosity, using accurate yet cost-effective methods. Presently, there exist several experimental methodologies to determine the porosity of such media. The present work showcases the adoption of a modified buoyancy method for determining the porosity content of a metal oxide sample of pure and K doped MgFe$_2$O$_4$. The samples were synthesized by the solid-state sintering method and the porosity of the samples were experimentally determined by using boiling water and water at room temperature as the immersion fluids. The theoretical density and total porosity were estimated from powder X-ray density analysis. Field emission scanning electron microscopy (FESEM) was employed to gain further clarity on the effect of doping on the grain size. This study aims to showcase a valuable combination of the modified buoyancy method with X-Ray density analysis for the characterization of porosity in suitable samples.