Correlation between structure, cation distribution, elastic, and magnetic properties for Bi3+substituted Mn–Zn ferrite nanoparticles

Abstract

Chemical coprecipitation was used to synthesize Mn<inf>0.6</inf>Zn<inf>0.4</inf>Bi<inf>x</inf>Fe<inf>2-x</inf>O<inf>4</inf> ferrite nanoparticles with x values from 0.0 to 0.05. XRD indicated nanocrystalline spinel phase with typical crystallite size of 6 nm after Rietveld refinement. The IR spectra show two strong absorption bands. Using IR data, the force constant was estimated for the tetrahedral and octahedral locations to get the C<inf>11</inf> and C<inf>12</inf> stiffness constants. Elastic moduli (Young, bulk, and rigidity), Poisson ratio, and Debye temperature were calculated using stiffness constants and all decreased with Bi³⁺ content. All nanoparticles studied are superparamagnetic and lose magnetism with Bi³⁺ concentration. The behaviors of all these parameters were explained by linking them to the structural changes that are introduced due to Bi³⁺ ion substitution. Moreover, different models were used to check and compare between both theoretical and experimental values for many parameters. Finally, the magneto-mechanical properties of the ferrite nanoparticles open the door for several daily applications.