SCS-Assisted Synthesis of EuFeO3 Core-Shell Nanoparticles: Formation Process, Structural Features, and Magnetic Behavior

Abstract This work reports an original approach to the synthesis of composite “core-shell” nanoparticles of o-EuFeO3@am-EuFeO3 via solution combustion synthesis (SCS) followed by heat treatment in the air. PXRD, 57Fe and 151Eu Mossbauer spectroscopy, FTIR, DSC-TGA, SEM-EDX, TEM-SAED and vibrating-sample magnetometry were used to analyze the as-prepared and heat-treated samples. It was shown that the formation of amorphous am-EuFeO3 “shell” on the surface of crystalline o-EuFeO3 “cores” arises from the partial carbonatization of europium oxide during the solution combustion. It was found that the average crystallite size of o-EuFeO3 “cores” (37-92 nm) and thickness of am-EuFeO3 “shell” (1-10 nm) can be easily varied through the simple temperature change of heat treatment in the range of 500-900°C. Acquired composite nanoparticles o-EuFeO3@am-EuFeO3 demonstrate uniform isometric morphology with a well distinct core and shell. Magnetometry results indicate the paramagnetic behavior of composite nanoparticles in a wide range of temperatures and applied magnetic fields that contradict the Mossbauer spectroscopy results showing the magnetic ordering of Fe-sublattice of o-EuFeO3 “cores”. Thus, the results of this work confirm the possibility of obtaining a new class of rare earth orthoferrite nanomaterials with the core-shell structure that can have promising functional applications.