Effect of Temperature on the Structural and Magnetic Properties of NixCo1 – xFe2O4 Nanoparticles

Authors V.S. Bushkova

Vasyl Stefanyk Pre-Carpathian National University, 57, Shevchenko Str., 76025 Ivano-Frankivsk, Ukraine

Е-mail bushkovavira@gmail.com
Issue Volume 8, Year 2016, Number 1
Dates Received 28 December 2015; published online 15 March 2016
Citation V.S. Bushkova, J. Nano- Electron. Phys. 8 No 1, 01002 (2016)
DOI 10.21272/jnep.8(1).01002
PACS Number(s) 75.50.Tt, 81.07.Wx, 81.20.Fw, 75.30.Kz
Keywords Sol-gel technology, Nickel-cobalt ferrite, Lattice parameter, Specific surface area, Initial permeability, Curie temperature.

In work ferrite single phase ferrite powders of systems NixCo1 – xFe2O4 were synthesised using sol-gel technology with participation of auto-combustion. It was found that the average size of coherent scattering regions not exceeding 62 nm. The dependences of the lattice parameter, X-ray density and specific surface area of the ferrite powders from nickel content were found. The unit cell parameter a decreases linearly with the nickel concentration due to smaller ionic radius of nickel. After annealing at a temperature of 1300 °C of ferrite powders, which were pressed in the form of toroid at pressure of 3.3·108 Pa, X-ray analysis showed that the received rings are single phase with the cubic structure of spinel space group Fd3m. Dependence of the initial permeability from the degree of substitution of cobalt cations on nickel cations is obtained. It is revealed that the crystallite size has a significant influence on the magnetic properties of the samples. With decreasing of crystallite size of nickel-cobalt ferrite Curie temperature decreases. Because of strengthening of the A-B exchange interaction the increase the Curie temperature occurs with increasing parameter x. It is shown that the smaller the particle size, the greater the thickness of the surface layer with significant violations of magnetic structure.