Title :
Microwave absorbing properties of Co-substituted Ni/sub 2/W hexaferrites in Ka-band frequencies (26.5/spl sim/40 GHz)
Author :
Yong-Jin Kim ; Sung-Soo Kim
Author_Institution :
Dept. of Mater. Eng., Chung-Buk Nat. Univ., Cheongju, South Korea
Abstract :
Summary form only given. The purpose of this study is to investigate the magnetic (static, high-frequency) and microwave absorbing properties of Co-substituted Ni/sub 2/W hexaferrites in the frequency range of Ka-band (26.5/spl sim/40 GHz). The powders of composition BaNi/sub 2-x/Co/sub x/Fe/sub 16/O/sub 27/ were prepared by calcining at 1250/spl deg/C, where the substitution ratio x was varied from 0.0 to 2.0. With the calcined powders, the composite specimens were prepared using silicon rubber as a matrix material. The saturation magnetization and the coercivity were measured using a VSM. The complex permeability and dielectric constant were determined from the measured reflected and transmitted scattering parameters using a WR-28 rectangular waveguide and HP8722D network analyzer.
Keywords :
barium compounds; cobalt compounds; coercive force; electromagnetic wave absorption; ferrites; ferromagnetic resonance; magnetic anisotropy; magnetic permeability; magnetisation; nickel compounds; 1250 C; 26.5 to 40 GHz; BaNi/sub 2-x/Co/sub x/Fe/sub 16/O/sub 27/; Co-substituted Ni/sub 2/W hexaferrites; HP8722D network analyzer; Ka-band frequencies; WR-28 rectangular waveguide; coercivity; complex permeability; dielectric constant; microwave absorbing properties; saturation magnetization; substitution ratio; Calcination; Dielectric measurements; Frequency; Iron; Magnetic properties; Matrices; Powders; Rubber; Saturation magnetization; Silicon;
Conference_Titel :
Magnetics Conference, 2002. INTERMAG Europe 2002. Digest of Technical Papers. 2002 IEEE International
Conference_Location :
Amsterdam, The Netherlands
Print_ISBN :
0-7803-7365-0
DOI :
10.1109/INTMAG.2002.1000925
