Journal of Advanced Materials in Engineering (Esteghlal)

---

The particles of ferrite Ni0.6-xCuxZn0.4Fe2O4, (0-0.5 in step with 0.1) were prepared by the sol-gel method. Sintering process of powders was carried out at 600, 800 and 1000 oC. The effect of the sintering temperature and chemical composition on the structural and magnetic properties of the Cu substituted NiZn ferrite was investigated. EDS analysis and X-ray diffraction patterns confirmed a well defined of single crystal phase with spinel structure. The thermal behavior process and particle size of samples were investigated by thermal analysis TG, DTA techniques and scanning electron microscope, respectively. VSM curves reveal that the sintering temperature and copper content affect saturation magnetization. M ssbauer spectra displays that the copper cations occupy the octahedral sites. With increasing of copper cations, the iron cations immigrate to tetrahedral site, consequently the saturation magnetization decrease.

---

In this study, nine Nd-Fe-B and FeCe thin films with 10-50 nanometers width were prepared by RF magnetron sputtering on the Si/SiO₂ substrate. Then, the films were annealed at 800 ^oC for 5 sec in rapid thermal annealing furnace. X-ray diffractometry (XRD) was used to analyze the phase composition of layers and existance of Nd₂F₁₄ and Fe₆₅Co₃₅ phase was confirmed, without formation of any other secondary phase. The layers surfaces were investigated using Field Emission Scanning Electron Microscope (FESEM). The morphology of layers surfaces was investigated using Atomic Force Microscope (AFM). The magnetic properties of layers were evaluated by vibrating sample magnetometer with maximum applied field of 24kOe, in order to measure coercivity, saturation of magnetization, hysteresis area, rectangular ratio and (BH)max. It was found that all layers have vertical magnetic anisotropy. Increasing thickness of FeCo resulted in increasing saturation of magnetization,  coercivity and saturation magnetization. The results indicate that by an increase in thickness of FeCo up to 20nm, exchange interaction strength between hard and soft magnetic layers is enhanced and, consequently, maximum energy induced from this hetero-structure is increased.