Exploring the role of Fe substitution on electronic, structural, and magnetic properties of La 2 NiMnO 6 double perovskites

A deep insight into the electronic, structural, and magnetic properties of single-phase polycrystalline La2Ni1-xFexMnO6 double perovskites has been presented. X-ray photoelectron spectroscopy revealed that the Fe substitution resulted in a mixed-valence state for Ni and Mn in all samples. Rietveld analysis of the powder X-ray diffraction data suggested that all samples exhibited the orthorhombic structure with the Pbnm space group. Raman spectroscopy measurements indicated an increase in disorder of the system with Fe doping. The mixed-valence states and the accompanied disorder enhanced the competing magnetic exchange interactions in the samples resulting in a reduction of the ferromagnetic phase transition temperatures and saturation magnetic moments of the system.