Nanosize ferrites obtained by ball milling: Crystal structure, cation distribution, size-strain analysis and Raman investigations

Spinels samples Fe 2.85Y 0.15O 4 (S1) and Fe 2.55In 0.45O 4 (S2), such as Fe 3O 4+ γ-Fe 2O 3 (S3) were obtained by ball milling. TEM micrograph as well as XRPD line broadening analyses show nanosize nature of the ferrite powders. Cation distribution, found by Rietveld refinement of the site occupancies, indicate Y 3+ ions presence at 16d sites in Fe 2.85Y 0.15O 4, and a random In 3+ ions distribution on both 8a and 16d sites in Fe 2.55In 0.45O 4 (space group Fd 3 ¯ m ). From the XRPD line broadening analysis crystallite size and strain values were determined. The crystallite size and strain anisotropy is significant, especially for Fe 2.85Y 0.15O 4 and Fe 2.55In 0.45O 4. This result is discussed regarding the influence of the cation substitutions. The Raman signature confirms the spinel structure and the homogeneity of the particles.