Structural and microwave behavior of Dy 3+ -substituted Ni 0.5 Zn 0.5 Dy x Fe 2-x O 4 ferrites

The enhancement of microwave absorbing properties in dysprosium ion (Dy3+)-substituted nickel–zinc ferrites (Ni0.5Zn0.5DyxFe2-xO4; x = 0.00, 0.01, 0.03, 0.05, 0.07 and 0.09) has been investigated in this work. The ferrite powders were synthesized by microwave-hydrothermal method and then powders were densified at 900 °C for 40 min using microwave furnace. The samples’ structural and morphological properties were studied using X-ray diffraction and scanning electron microscopy (SEM), respectively. The structural result confirms the spinel phase under low Dy3+ content, like the pure Ni–Zn ferrite, while a secondary phase of DyFeO3 appears after the content of Dy3+ exceeds a certain limit (x > 0.07). Morphological analysis from the SEM images reveals the formation of spherical grains of the samples. DC resistivity of the samples has been measured using two-probe method. Magnetic hysteresis data confirm the soft magnetic nature of the samples. The vector network analyzer results show that adjusting the content of Dy3+ is significant in changing the magneto-dielectric properties and microwave absorption capacity of the materials. The composition x = 0.07 sample showed a reflection coefficient of − 33.24 dB at the frequency and bandwidth of 10.31 GHz and 2.59 GHz for an absorber thickness of 2.5 mm for losses less than − 10 dB. This acquired result indicates that the investigated samples could be used as a microwave absorber application in X-band.