Structural and magnetic properties of chemically synthesized yttrium-substituted nickel nanoferrite

In this paper, yttrium-substituted nickel ferrite (NiY۲xFe۲-۲xO۴) nanostructures were synthesized via the co-precipitation method with different concentrations of yttrium (x = ۰.۰۰, ۰.۰۲, ۰.۰۶, and ۰.۱۲ %, where x is the dopant concentration in molar percent) after calcination at ۵۰۰ ºC. Structural studies of the samples were analyzed using X-ray diffractometry (XRD) technique. XRD results showed that the addition of Y led to an increase in synthesized nanoparticles. Molecular studies have been done using Fourier transform infrared (FT-IR) spectroscopy. FT-IR results showed that the bands at about ۵۵۰-۵۶۰ and ۴۳۳ cm-۱ are associated with tetrahedral and octahedral Metal-O bonds, respectively. Field emission scanning electron microscopy (FE-SEM) exhibit that adding  Y۳+ ions dopant up to x = ۰.۰۶ led to a considerable decrease in the powders’ particle size. Adding more dopant up to x = ۰.۱۲ led to an amorphous and crystalline phase formation. The size of nanoparticles before substitution estimated from FE-SEM images were ۳۹.۴۹, ۳۶.۴۹, and ۵۰.۷۸ nm, which increased to ۶۳.۰۷, ۶۴.۰۲, and ۷۳.۵۶ nm after the substitution, respectively. The magnetic behavior of the samples was investigated using vibrating sample magnetometry (VSM) at room temperature (RT). VSM results showed that the saturation magnetization and coercivity (Hc) values decreased with the increase of yttrium contents up to x = ۰.۱۲. This was referred to as the redistribution of cations on the octahedral bonds.

کلیدواژه ها:

Yttrium-nickel ferrite ، ferromagnetic ، saturation magnetization ، coercivity