World Applied Sciences Journal 17 (6): 739-741, 2012 ISSN 1818-4952 © IDOSI Publications, 2012 Corresponding Author: M. Niyaifar, Science and Research Branch, Islamic Azad University, Khouzestan, Iran. Tel: +989351055293, Fax: +986114457612. 739 Synthesis of Zinc Ferrite Nanoparticles M. Niyaifar, A. Ahmadi and A. Hasanpour Science and Research Branch, Islamic Azad University, Khouzestan, Iran Abstract: Zinc ferrites have been prepared by conventional (Z1) method and mechanochemical processing (Z2) for comparing their structural properties. The X-ray diffraction (XRD) and transmission electron microscopy (TEM) is used to study on structural properties. The XRD pattern shows single phase of spinel ferrite structure. The average crystallite size estimated by using Scherrer’s equation was 35 and 90 nm for Z2 and Z1 respectively. The XRD results shows lattice parameter of Z2 is larger than that of Z1, which has smaller particle size. It is attributed to the effect of the smaller particle size and interface structure with a larger volume fraction. Key words: INTRODUCTION magnetic field parallel to the direction of gamma rays Zinc ferrite has long attracted researchers’ interests synthesized by conventional method as well as ball because of its intriguing magnetic properties compared milling are studied. Microstructures properties of the with other spinel ferrites. The traditional bulk ZnFe O samples are studied using a X-ray diffraction, 2 4 belongs to the normal spinel type with antiferromagnetic transmission electron microscopy (TEM). properties below the Néel temperature of about 10.5K and behaves paramagnetic at room temperature. All the Zn Experimental Studies: In Conventional preparation 2+ ions reside in the tetrahedral sites (A sites) and the Fe (Z1), a dry mixture of ZnO and -Fe O is annealed at 3+ ions are totally in the octahedral sites (B sites). In 1961, 1100°C; the progress of the formation of the ferrite is Néel suggested that small antiferromagnetic particles monitored by XRD analyses at different time intervals. can exhibit superparamagnetism and weak The presence of octahedral zinc cation is observed ferromagnetism due to uncompensated spins in the along with the regular tetrahedral Zn in the sample that two sublattices [1]. In recent years, magnetic properties had undergone 30 minute heat treatment. After three of many antiferromagnetic oxides, such as NiO [2, 3], hours of heating, pure normal zinc ferrite is formed. For MnO [4], CoO [5] and hematite [6,7], were experimentally ball milling preparation (Z2), commercial coarse-grained studied. It was suggested that this might be resulted powder of ZnFe O are milled in a high energy SPEX by the reduced coordination of the surface spins [2]. 8000D Mixer / Mill. In this method 5 g charges are sealed Recently, ZnFe O nanoparticles prepared using in a steel vial under an Ar atmosphere with two 11.5 mm 2 4 various methods, such as traditional ceramic synthesis diameter and four 6.2 mm steel balls, yielding a ball-to- [11], aerogel procedure [9-13], low-temperature power weight ratio of 3.5:1. X-ray diffraction (XRD) hydroxide coprecipitation and hydrothermal synthesis measurement was performed on a Philips X’Pert type [13], have been studied and observed to be diffractometer with CuK radiation to study the crystal ferrimagnetic or superparamagnetic. The origin of the structure and the phase composition. A JEOL 2000 FXII ferrimagnetic properties of ZnFe O and other spinel type transmission electron microscope (TEM) is used to 2 4 ferrite nanoparticles was studied using low-temperature observe the morphology and the size distribution of the transmission Mossbauer spectrometer with applied nanoparticle samples. [10, 11]. In this paper, ZnFe O nanoparticles were 2 4 2 3 2 4 1