Synthesis and Magnetic Properties of Znco-Ferrite Nanoparticles Prepared Using Co-Precipitation Method

Zinc-cobalt ferrite nanoparticles (NPs) were synthesized using co-precipitation method. In the present process, NPs precipitated at various pHs, then calcined at 750°C for 2 h. X-ray diffraction (XRD) analysis confirmed single phase of ZnCo ferrite phase in all of the samples. Williamson-Hall calculations showed that the strain value in the microstructure of specimen prepared at pH= 8 is equal to -7*10-4. This content for pHs of 11 and 14 increased to 10-4 and 10-3, respectively. Therefore, the highest crystallite diameter was obtained as 51.35 nm for prepared NPs at pH= 14. Field emission scanning electron microscopy (FESEM) showed a relatively uniform distribution of particles with average size of 9.38, 50.1 and 30.7 nm for prepared powders at pHs equal to 8, 11 and 14, respectively. Vibrating sample magnetometer (VSM) measurements revealed that saturation magnetization (MS), anisotropic constant (K) and Bohr magneton (nB) characteristics are different at various pHs. So that, these parameters were obtained as 95.48 emu/g, 14.614*103 and 4.06, respectively for prepared powders at pH= 8, while at pH= 11 increased to 100.34 emu/g, 15.358*103 and 4.27, then changed to 81.98 emu/g, 11.712*103 and 3.49 at pH= 14. It was found different conditions of particles precipitation have a remarkable role on the properties of produced NPs.