Synthesis and Ferrimagnetic Behaviour of Mn Doped Rare Earth Iron Garnets

Rare earth iron garnets R₃Fe_5–xMn_xO₁₂(R=Pr, Nd, Sm, Eu) were prepared through mild hydrothermal method. The initial alkalinity of solutions was thought to play an important role in governing the content of Mn. The effect of substitution Fe³⁺ ions by Mn³⁺ ions on magnetic properties was investigated. The saturation magnetizations of Mn-doped samples are larger than that of corresponding parent compounds due to the moment of Mn³⁺ ion being smaller than that of Fe³⁺. It is clearly shown that incorporation of Mn³⁺ gives rise to significant variations in the Curie temperature. With increasing of Mn content x, Curie temperatures reduced sharply for the garnets, which could be explained by the exchange interaction between a-d Fe³⁺ being reduced in these compounds.