Article ID Journal Published Year Pages File Type
1624122 Journal of Alloys and Compounds 2009 9 Pages PDF
Abstract

Ni-, Ti-substituted nanocrystalline M-type barium hexaferrite powder (BaNixTixFe12−2xO19 (x = 0.4) of size ∼10 nm) was coated with Ni-P by electroless (EL) coating technique to form EL Ni-P/BaNi0.4Ti0.4Fe11.2O19, a radar absorbing material (RAM) nanocomposite powder. Under TEM, the particle size of RAM powders before and after Ni-P coating were found to be in the range of 10–15 nm and 15–25 nm respectively. A uniform layer of 5–10 nm thick coating is deposited due to the controlled growth of EL Ni-P nanoglobules onto the powder. A growth mechanism was proposed to understand the deposition of EL Ni-P layer onto the RAM powder. The reflection loss (RL) of the EL (Ni-P)/RAM nanocomposite powder in Ku band (12.4 −18 GHz) was evidently enhanced to −28.70 dB, as compared to the EL Ni-P nanoglobules (−16.20 dB) and nanocrystalline RAM powder (−24.20 dB). After annealing at 400 °C for 4 h, the RL and bandwidth of EL (Ni-P)/RAM nanocomposite powder was further improved from −24.20 to −35.90 dB and 1.50 to 4.00 GHz respectively. The RL enhancement mechanism was explained on the basis of VSM study (hysteresis loops) and electromagnetic theory.

Related Topics
Physical Sciences and Engineering Materials Science Metals and Alloys
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