Effect of Zinc on Crystal Structure and Magnetic Properties of Co1-xZnxFe2O4 Nanoparticles Synthesized by Coprecipitation Method

The purpose of this study is to determine the effect of the addition of 2 % SrO on physical, magnetic properties and crystal structure of BaO6Fe2O3. In this study, the coprecipitation method was used with raw materials BaCl2, FeCl3 and SrCl3 and Ba-ferrite composition is used based on the ratio of mole BaO: Fe2O3 = 1: 6, while SrO is used 2% of the weight of Ba-ferrite. The raw materials are dissolved in distilled water, then added a solution (50%) of ammonia to form a perfect precipitate. The precipitate after filtering was dried in an oven at 100°C until dry, then crushed with mortar and partially taken for analysis with DTA / TG. The fine powder was calcined at 800 ° C and held for one hour using an electric furnace. The calcined samples were crushed with mortar and fine powder was added 1% wt.of PVA adhesive and formed with a pressure of 40 MPa to obtaine a pellet sample. The pellet samples were then sintered at 1150°C and hold for 1 hour. Furthermore, the sintered samples were characterized such as measurement of bulk density, magnetic properties with gauss meters and VSM and measurements with XRD. The results of characterization show that the addition of additives 2% of SrO can provide an increase in physical properties and magnetic properties (remanence). But for the crystal structure of XRD analysis there is no change, a single phase is formed, namely BaFe12O19.

Download Full-text

Calcination effects on the crystal structure and magnetic properties of CoFe2O4 nanopowders synthesized by the coprecipitation method

Revista Mexicana de Física ◽

10.31349/revmexfis.66.251 ◽

2020 ◽

Vol 66 (3 May-Jun) ◽

pp. 251

Author(s):

G. Márquez ◽

V. Sagredo ◽

R. Guillén-Guillén ◽

G. Attolini ◽

F. Bolzoni

Keyword(s):

Crystal Structure ◽

Magnetic Properties ◽

Coprecipitation Method ◽

Thermal Treatments ◽

Particle Sizes ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

The Mean ◽

Spectroscopy Studies

Cobalt ferrite nanopowders were successfully synthesized by the coprecipitation method and subsequent calcinations at 873 and 1073 K. The effects of the thermal treatments on the crystal structure, particle size and magnetic properties of the nanocompounds were investigated. The particle sizes were determined from transmission electron microscopy and an increase in sizes with the increment in calcination temperature was observed. The mean particle sizes were 29 and 42 nm, for samples calcined at 873 and 1073 K, respectively. By X-ray diffraction it was determined that the nanoparticles crystallized in the cubic spinel structure. Additionally, Fourier transform infrared spectroscopy studies confirms the presence of spinel metal oxide. The magnetization measurements as a function of the temperature and the applied magnetic field suggested that a large part of the nanoparticles calcined at 873 K present a superparamagnetic behavior at room temperature, while those calcined at 1073 K are mainly in the blocked regime at temperatures below 320 K. In addition, remarkably high coercivities of approximately 10.7 and 12.4 kOe were observed at low temperatures, for the nanopowders calcined at 873 and 1073 K, respectively.

Download Full-text