Synthesis, Structural Characterization, and Infrared Analysis of Double Perovskites Pr₂NiMnO₆, Gd₂NiMnO₆, and...

We synthesized Pr₂NiMnO₆, Gd₂NiMnO₆, and Er₂NiMnO₆ double perovskites in a nano-ceramic form by a sol-gel method. By means of room-temperature X-ray powder diffraction measurements, we determined the crystal structure of the three compounds, which is monoclinic, corresponding to a double perovskite structure, described by space group P2₁/n structure. From the determined structures, the bulk moduli were estimated to be 173-179 GPa. The average size particle of nanoparticles was determined from X-ray diffraction by the Langford method plot and by the Scherrer formula. The morphology and homogeneity of nanoparticles were analyzed by scanning electron microscopy. We found that they form compact agglomerations of approximately 200 nm in diameter. Fourier transform infrared spectroscopy measurements were performed, determining the absorption spectrum. The assignment of the measured infrared absorption bands is discussed.