Effect of double substituted m-barium hexaferrites on microwave absorption properties

role in determining the reflection and attenuation properties of incident microwaves. Their real (µ ′ and ε ′) and imaginary (µ ′ ′ and ε ′′) components and relationship with microwave absorbing properties have been investigated in the frequency range 8–16 GHz for doped M-type barium hexaferrites in polychloroprene (CR) matrices. Individual and simultaneous substitutions of Fe3+ ions by Co2+, Ti4+, and Mn3+, and of Ba2+ ions by La3+ and Na+ make possible the use of these materials as RAMs, due to frequency depend-ence of µ r * of hexaferrite, responsible for the location of its natural resonance. A double substitution of Ba2+ and Fe3+ (LaNaCoTiMn-BaHF) resulted in the best microwave absorption (99.9%) at the frequency of 15 GHz. Key words: microwave absorbing materials; doped ferrites; composites; waveguid