Influence of Nd3+ substitution on the microstructure and electromagnetic properties of barium W-type hexaferrite

The W-type ferrites doped with Nd3+, Ba1-xNdxCo2Fe16O27 (x=0.00, 0.05, 0.10, 0.15, 0.20 and 0.25), were prepared by sol-gel method. The effect of the substitution Nd3+ rare-earth ions for Ba2+ ions on the microstructure, complex permeability, permittivity and microwave absorption of the samples was investigated. All the XRD patterns showed the single phase of the W-type barium ferrite without other intermediate phase when x <= 0.25. With the increase of the substitution content of Nd3+ ions from 0.00 to 0.25. the values of the lattice constant (a) of the samples were nearly unchanged but that of (c) slightly decreased. SEM image showed that the grain was smaller, more perfect and homogeneous for the ferrites doped with Nd3+ than that of the pure ferrite. The real part of complex permittivity (epsilon') and imaginary part (epsilon '') increase with more addition of Nd3+ amount. The imaginary part of complex permittivity (mu '') increases and the real part (mu') goes down after Nd3+ is doped. Furthermore, the Nd3+ ions doped in the ferrite improved microwave absorbency. (C) 2009 Elsevier B.V. All rights reserved.