Sol-gel synthesis, surface and magnetic properties of nanocrystalline SmAlO3

Nanocrystals of single-phase samarium monoaluminate (SmAlO3) were synthesized and studied for the first time. Malic acid was employed as a new complexing agent in the sol-gel process. The material was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDS), specific surface area and density. The lowest size of the nanoparticles was about 50-60 nm and some of them formed agglomerates. The binding energies of core-level electrons of Sm (3d, 4d, 4f, 5p, 5s), Al (2s, 2p) and O (1s, 2s) in nanocrystalline SmAlO3 were obtained by X-ray photoelectron spectroscopy (XPS) and found shifted in respect to the corresponding values for the same elements. The temperature dependence of the AC magnetic susceptibility of the substance was determined between 2.5 and 250 K. The experimental molar magnetic susceptibility was compared with the theoretical one of Sm3+ ions. The nanomaterial was found paramagnetic in the specified temperature range with Curie-type paramagnetism below 12 K.