CORRELATION BETWEEN CHEMICAL COMPOSITION AND CURIE TEMPERATURE OF A NICKEL-COBALT FERRITE

Modifying the properties of spinel ferrites by doping allows significantly expanding their application in various fields of science and industry. The present work reports results of the study of Ni 1– x Co x Fe 2 O 4 ceramic samples ( x = 0-1 with a step of 0.1) prepared by solid phase synthesis. The morphology and size of the particles of the synthesized powders are determined. The monophase character of the synthesized materials is confirmed by X-ray powder diffraction. The unit cell parameter a,b,c increase from 8.3375(3) Å to 8.3819(4) Å upon the substitution of nickel by cobalt. The differential scanning calorimetry data indicate heat capacity jumps corresponding to a thermal second-order phase transition. The phase transition temperature depends on the ceramics composition and decreases monotonically from 596 °C to 530 °C as nickel is replaced by cobalt.