Enhancement of GHz electromagnetic wave absorption characteristics in aligned M-type barium ferrite Ba1-xLaxZnxFe12-x-y(Me0.5Mn0.5)yO19 (x=0.0-0.5; y=1.9-3.0, Me:: Zr, Sn) by metal substitution

The resonance absorption properties depend on the complex permeability mu = mu' - j mu, particularly mu = M-s/2H(A)alpha and x of substitution amount for Ba and y of that one for Fe on the absorption properties of Ba ferrite compound. The c-axis aligned Zr-substituted samples (x = 0.0; y = 1.4) showed M-s = 76 mu Wm/kg, H-A = 0.21 MA/m, and mu' = 7.2 and mu = 7.0. These mu' and mu are significantly larger than those for (TiMn)-substituted samples. Sn or Zr is concluded to be effective in enhancing the absorption characteristics of M-type Ba ferrite absorber. (C) 2003 Elsevier B. V. All rights reserved.