Magnetic susceptibility and surface properties of EuAlO3 nanocrystals

Nanocrystalline single-phase europium aluminate (EuAlO3) has been synthesized by modified sol-gel method with a new complexing agent – malic acid. The material has been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive analysis (EDS). The nanoparticles have an average size of 50 nm, a density of 7.01 g/cm3 at T = 293 K, a specific surface area 15.0 m2/g and form agglomerates. The binding energies of core-level electrons of europium, aluminium, and oxygen in EuAlO3 have been found by means of X-ray photoelectron spectroscopy (XPS) and compared with the values for the respective elements. The temperature dependence between 300 K and 2 K of the experimental AC magnetic susceptibility of EuAlO3 nanocrystals has been determined and compared with the theoretical one for Eu3+. It has been confirmed that the material is paramagnetic in the entire temperature range.

Research highlights
► A modified sol–gel method with the aid of malic acid has resulted in nanocrystalline europium monoaluminate (EuAlO3) at a relatively low temperature of synthesis.
► The single phase of the material has been confirmed by XRD.
► The binding energies of certain core-level electrons have been found chemically shifted in EuAlO3 and corresponding to ionic metal–oxygen bonds.
► The AC magnetic susceptibility measurements reveal that this nanomaterial is paramagnetic in the range 2–300 K with nearly Curie-type paramagnetism below 20 K.