Magnetic properties, structural studies and microwave absorption performance of Ba0.5Sr0.5CuxZrxFe12-2xO19/Poly Ortho-Toluidine (X=0.2,0.4, 0.6, 0.8) ceramic nanocomposites

Author(s):  
S. Shooshtary Veisi ◽  
M. Yousefi ◽  
M.M. Amini ◽  
A.R. Shakeri ◽  
M. Bagherzadeh ◽  
...  
NANO ◽  
2015 ◽  
Vol 10 (05) ◽  
pp. 1550070 ◽  
Author(s):  
B. B. Zhang ◽  
P. F. Wang ◽  
J. C. Xu ◽  
Y. B. Han ◽  
H. X. Jin ◽  
...  

Owing to the unique microstructure and the excellent dielectric properties, carbon nanotubes (CNTs) were decorated with CoFe 2 O 4 nanoparticles to synthesize the CoFe 2 O 4/CNTs nanocomposites by the solvothermal method. The phase structure, morphology, magnetic properties and microwave absorption performance of the as-prepared CoFe 2 O 4/CNTs were characterized and discussed by X-ray diffraction (XRD), thermal gravity analysis (TGA), transmission electron microscope (TEM), vibrating sample magnetometer (VSM) and vector network analyzer (VNA). All results indicated that the diameter of CoFe 2 O 4 nanoparticles decorating on the surface of CNTs increased with the solvothermal temperature. CoFe 2 O 4/CNTs prepared at 180°C, 200°C and 220°C exhibited superparamagnetism, while the other samples presented ferromagnetism at room temperature. And with the increasing solvothermal temperature, the saturation magnetization and coercivity increased up to 72 emu/g and 2000 Oe for the sample prepared at 260°C (S-26). And the reflection loss of CoFe 2 O 4/CNTs nanocomposites increased with the solvothermal temperature up to -15.7 dB for S-26 with the bandwidth of 2.5 GHz.


Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2921 ◽  
Author(s):  
Wei Huang ◽  
Yujiang Wang ◽  
Shicheng Wei ◽  
Bo Wang ◽  
Yi Liang ◽  
...  

Hollow magnetic structures have great potential to be used in the microwave absorbing field. Herein, Fe3O4 hollow spheres with different levels of hollowness were synthesized by the hydrothermal method under Ostwald ripening effect. In addition to their microstructures, the microwave absorption properties of such spheres were investigated. The results show that the grain size and hollowness of Fe3O4 hollow spheres both increase as the reaction time increases. With increasing hollowness, the attenuation ability of electromagnetic wave of Fe3O4 spheres increases first and then decreases, finally increases sharply after the spheres break down. Samples with strong attenuation ability can achieve good impedance matching, which it does preferentially as the absorber thickness increases. Fe3O4 hollow spheres show the best microwave absorption performance when the reaction time is 24 h. The minimum reflection loss (RL (min)) can reach −40 dB, while the thickness is only 3.2 mm.


Sign in / Sign up

Export Citation Format

Share Document