Nickel–Yttrium Ferrite Nanopowders for Solving Environmental Problems

Abstract

Among the family of spinel ferrites, nickel ferrite NiFe 2 O 4 obtained by ceramic technology was widely studied due to its tremendous properties such as high electromagnetic performance, excellent chemical stability and mechanical hardness, and moderate saturation magnetization, making it as a good contender for the application as soft magnets and low-loss materials at high frequencies. The structure, mechanical, magnetic, electrical, and dielectric properties of nickel ferrite are dependent on several factors including the method of fabrication, sintering time and temperature, chemical composition, type and amount of dopant, grain structure. The sol-gel processing with autocombustion (SGA) technique was used for the synthesis of NiY x Fe 2x O 4 (x0.0, 0.1, 0.2, 0.3, 0.4, 0.5) ferrite nanoparticles. The mixed solution was dried at temperature around 403 K. During evaporation, the solution becomes viscous and finally formed as a xerogel. At further elevation of temperature, the organic constituents are decomposed with the generation of gases such as CO 2 , N 2 and H 2 O; therefore, the xerogel automatically ignited. The autocombustion was completed within a few seconds, yielding the nanopowders of nickel-yttrium ferrites. The XRD results confirm single-phase formation of the as-prepared NiFe 2 O 4 sample. The powders substituted with Y 3 ions, except the spinel-type phase, contain additional -Fe 2 O 3 and Y 2 O 3 phases too. The powder sizes decrease from 43 nm to 17 nm with increase in amount of Y 3 ions. The EDX results confirm the presence of Ni, Fe, Y, and O elements in Ni-Y-ferrite powders. The infrared (IR) spectra were recorded at the room temperature in the range from 400 cm 1 to 4000 cm 1 ; they confirm the spinel structure. As found, the adsorption capacity of Ni-Y ferrite increases, while the substitutions with Y 3+ ions increase. The adsorption process increases with increasing pH, has a maximum at pH7, and depends on the dye type.Серед феритів зі структурою шпінелі властивості фериту ніклю NiFe 2 O 4 , одержаного за керамічною технологією, є широко вивчені, оскільки він