Synthesis of dysprosium doped cobalt ferrites nanoparticles by solgel auto-combustion method and influence of grinding techniques on structural, Morphological, and magnetic properties
Chnar Aziz, Bruska Azhdar
Abstract
The synthesis of Dysprosium (Dy3+) doped cobalt ferrite nanoparticles CoFe2−xDyxO4 (x = 0.00, 0.02, 0.04, 0.06, 0.08) via solgel auto-combustion route was introduced. To improve the grinding process of the synthesized nano-powders, a new grinding technique (ultrasonic wet-grinding) was applied alongside the traditional grinding technique (manual dry-grinding), and the effects on the structural, morphological, and magnetic properties were investigated. The formation of face centered cubic spinel ferrite was confirmed by X-ray diffraction studies. The crystallites size was decreased with increasing Dy3+ concentration. Bulk density is increased considerably by ∼150 % and porosity is decreased by ∼11% due to ultrasonic wet-grinding technique for sample when x = 0.06. Transmission Electron Microscopy and Scanning Electron Microscopy were used to study the morphological properties. The Dy3+ doping and ultrasonic-grinding technique also resulted in a narrower grain size distribution. Pureness and the presence of constituent elements Co, Fe, Dy, and O were confirmed by energy dispersive X-ray spectra. Due to sonication, the Dy weight percent increased by 78.26 % for (x = 0.04). The two dominant absorption bands (υ1 and υ2) in FTIR spectra are related to tetrahedral and octahedral sites, respectively. The value of υ1 and υ2 for manual dry-grinded powders was almost stable while they fluctuated for ultrasonic wet-grinded powders. A Vibrating Sample Magnetometer (VSM) was used to examine the magnetic properties at room temperature. The maximum coercivity obtained in manual dry-grinded powder when (x = 0.02) and the minimum saturation magnetization obtained in ultrasonic wet-grinded powder when (x = 0.08).