M¨ossbauer spectral analysis and magnetic properties of the superparamagnetic Mn0.5Zn0.5Fe2O4 ferrite nanocomposites

Manganese-zinc (Mn-Zn) ferrites of the composition Mn0.5Zn0.5Fe2O4 are synthesized by solid-state reactions. Portions of the synthesized material are then ball milled for 1, 2, 4, 8, and 12 h. Their physical properties are subsequently analyzed by XRD, ossbauer ¨ spectroscopy, and magnetization measurements. The XRD analysis reveals the cubic spinel structure for all milled samples. Upon ball milling, however, the crystalline size decreased while the microstrain increased significantly. Moreover, the magnetic order is enhanced by ball milling, as shown by the Mossbauer ¨ effect and magnetization measurements. The observed magnetic charac teristics are consistent with ball milling changing the chemical order at the two sites of the spinel structure. The distribution of cations for the composition of these samples is suggested by considering the Fe3+ ions amounts that exist at the octahedral and tetrahedral sites. Interestingly, the milling process played a crucial role in enhancing the magnetization of these Mn-Zn ferrites. The remarkable magnetization of these Mn-Zn ferrites is useful for energy-related applications.