Studies on structural, electronic and magnetic properties of La3+ ion-substituted Ho2FeMnO6 double perovskite compounds

The advantage of exchanging lanthanides and transition metal ions make the double perovskite structured materials yield with the important prospects for the study towards applications. The double perovskite material, Ho2FeMnO6 has been phase stabilized using the conventional solid-state reaction technique. The effect of La substitution on the properties of the Ho2FeMnO6 is also carried out. The structural stability of the prepared compounds is confirmed using the XPS study which confirms the oxidation states of Ho, La, Fe and Mn to be +3. Similarly, the formation of the double perovskite structure is confirmed using the Rietveld refinement of powder X-ray diffraction data by following HoFeO3 as the starting model. The prepared compounds crystallized in orthorhombic structure with Pbnm space group. The La3+ substitution marginally increases the cell volume as it has bigger ionic radius than that of Ho3+ ion. The morphology comparison of the pure and the La-substituted Ho2FeMnO6 compounds does not show any major variation. The magnetization study of Ho2FeMnO6 compound reveals the antiferromagnetic property arising from the fact of Fe3+ and Mn3+ ions have almost similar magnitude of magnetic moment aligned anti-parallel to each other. It is further inferred that the substitution of La3+ ions marginally reduces the magnetic response of the materials. All the characterization studies confirm that the Ho2FeMnO6 double perovskite structure has been formed and the substitution of trivalent lanthanide (La3+) has shown with marginal effect on the physical properties of the materials.