Magnetic and electromagnetic properties of hard-soft Sr0.5Ba0.5SnxFe12-xO19/CoFe2O4 nanocomposite

Magnetic nanocomposites (NCs) consisting of Sn substituted Ba/Sr hexaferrite (HFs) and cobalt ferrite as the hard (H) and the soft (S) phases respectively, H/S Sr0.5Ba0.5SnxFe12-xO19/CoFe2O4 (x <= 0.06) NCs (H/S Sr0.5Ba0.5SnxFe12-xO19/CFO(x <0.06) NCs), were formed via one pot in situ Sol-gel approach using Citric acid as fuel. After that solid product was calcinated at 900 degrees C for 3 h. XRD analysis and Rietveld refinement confirmed the formation of desired products with the absence of any impurity. Electron microscopy (Transmission and Scanning) techniques (SEM along EDX, TEM and HR-TEM) proved the existence of both cubic and hexagonal morphology and their chemical compositions. The diverse NCs exhibited ferrimagnetic behavior at both room (RT) and low temperatures. M-H results reveal the presence of kinks in their hysteresis loops, reflecting that the exchange coupling effect was not accomplished. The Ms, s , Mr r and Hcvalues c values increase as the Sn content increases. Then, they start to decrease for higher Sn content. It is evident that the Sn doping in the studied H/S NCs is helpful to intensify the degree of exchange coupling effect over the dipolar interactions. Microwave characteristics of the H/S Sr0.5Ba0.5SnxFe12-xO19/CFO NCs were explored in the range 8-12 GHz. Frequency dispersions of the real/imaginary parts of permeability and permittivity were determined from S11-S21 parameters. RL coefficient demonstrated intensive electromagnetic absorption with average level- 8...-13 dB in this frequency range that corresponded to the absorption of the natural media. RL coefficient demonstrated intensive electromagnetic absorption with average level- 8...-13 dB in this frequency range that corresponded to the absorption of the natural media.