Microwave-induced combustion synthesis of Li0.5Fe2.5−xMnxO4 powder and their characterization

Li0.5Fe2.5−xMnxO4 (0 ≤ x ≤ 1.0) powders with small and uniformly sized particles were successfully synthesized by microwave-induced combustion, using lithium nitrate, ferric nitrate, manganese nitrate, and carbohydrazide as the starting materials. The process takes only a few minutes to obtain as-received Mn-substituted lithium ferrite powders. The resultant powders annealed at 650 °C for 2 h and were investigated by thermogravimeter/differential thermal analyzer (TG/DTA), X-ray diffractometer (XRD), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and thermomagnetic analysis (TMA). The results revealed that the magnetic properties and Curie temperature of Mn-substituted lithium ferrite were strongly affected by Mn content.