Strong and weak ferromagnetic of cobalt ferrite: Structural, magnetic properties and reflection loss characteristic

In this research, we investigated the effect of strong and weak ferromagnetic cobalt zinc ferrite dopant ion La3+ on the reflection loss characteristics measured at the X-band frequency (8–12 GHz). Strong and weak ferromagnetic cobalt zinc ferrite dopant ion La3+ was synthesized by solid state reaction using mechanical milling technique then sintered at 1000 °C for 5 h. Single-phase cobalt ferrite Co0.75Zn0.25Fe2-xLaxO4 and Co0.25Zn0.75Fe2-xLaxO4 (x = 0.02, 0.04, 0.06, and 0.08) with a cubic structure has been successfully formed. Particle morphology and elemental composition have also observed using a scanning electron microscope and energy dispersive spectroscopy, respectively. Meanwhile magnetic properties were characterized by using vibrating sample magnetometer in the form of a hysteresis curve. The presence of Zn in the cobalt ferrite structure that can distinguish between strong and weak ferromagnetic. The results of surface morphology observations show that the sample has a relatively uniform shape and particle size distribution and the results of this elementary analysis show that the phase composition of the two types of samples is in accordance with the expected composition. This research has obtained the most optimum composition and can produce relatively large microwave absorption at the composition of Co0.75Zn0.25Fe2-xLaxO4 with the dopant ion La3+, x = 0.08 with a maximum RL value of −27dB, −25 dB, and −15dB which respectively at the frequencies of 8.4 GHz, 10.2 GHz and 11.2 GHz.