Tailoring the structure and properties of GdMnO3 ceramics via Fe substitution

This study focuses on the regulatory effects of structural evolution and vacancy defects induced by Fe-ion substitution at the Mn site on the physical properties of gadolinium manganite (GdMnO 3 ) materials synthesized via the solid-phase reaction method. The single-phase structure of synthesized GdMn 1- x Fe x O 3 ceramics was confirmed by X-ray diffraction (XRD) and Raman analyses, and lattice deformation due to the substitution of Mn ions with Fe ions in GdMnO 3 was observed. X-ray photon spectroscopy (XPS) results confirmed the presence of Fe 2+ /Fe 3+ and Mn 4+ /Mn 3+ in the GdMn 1- x Fe x O 3 samples, and their mutual interactions led to changes in their relative concentrations. Positron annihilation spectroscopy results indicated that Fe 3+ substitution significantly influences the size and concentration of vacancy defects in the GdMn 1- x Fe x O 3 system. Temperature and magnetic field dependent magnetization measurements revealed that Fe-ion substitution could improve the magnetic properties of GdMnO 3 . Compared with the magnetic moment contribution from Fe ions, the double-exchange interaction between Mn 3+ and Mn 4+ ions, cation vacancies, and lattice distortion caused by Fe ion substitution exerted more dominant influence on the magnetic properties of GdMnO 3 . These results demonstrate that the introduction of vacancy defects and the conversion of Mn 3+ to Mn 4+ represent an effective strategy for optimizing the properties of the GdMnO 3 system.