Phase stabilization of Fe substituted NdMn2O5 ceramics and their properties

• First time report on a material of stoichiometry NdFeMnO5.
• Synthesis using high-energy ball milling assisted technique.
• Magnetic transition temperature shifts to ∼290 K when compared to parent NdMn2O5 (∼75 K).
• Majority, Mn and Fe determined to be in +4 and +3 oxidation states respectively.
• Fe3+ with high magnetic moment modifies the magnetic behavior considerably.

An oxide of stoichiometry, NdFeMnO5, has been synthesized using a two-step process. First the precursor oxides are high-energy ball milled and the as-milled powders are then sintered to obtain the NdFeMnO5 phase. Rietveld refinement of the XRD pattern, by replacing the Mn3+ sites with Fe3+, shows the formation of stoichiometric NdFeMnO5. Nd & Mn are found to be in +3 and +4 states, respectively from the XPS study. Agglomeration of fine grains is evident from the electron micrographs. Fe3+ has a magnetic moment higher than Mn3+, and hence affects the magnetic property. Thermo-magnetization measurements show the existence of magnetic ordering below 290 K. An increase in magnetization at low temperature is also observed due to ordering of R3+ moments in addition to Fe and Mn spin moments. A linear increase in conductivity and stable dielectric response is observed from impedance study at high temperature.

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