Microwave ferromagnetic resonance of cobalt and nickel substituted U-type hexaferrites

Abstract

This paper presents accurate broad-band data on the complex relative permittivity (/spl epsiv/=/spl epsiv/'-j/spl epsiv/") and complex relative permeability (/spl mu/=/spl mu/'-j/spl mu/'') of two U-type hexaferrites. These hexaferrites have a general molecular formula of Ba/sub 4/Me/sub 2/Fe/sub 36/O/sub 60/ where Me is a bivalent transition-metal. In this work, Me=Co, Ni. In this paper, the dielectric and magnetic properties of these two U-type hexaferrites, Co/sub 2/U and Ni/sub 2/U, are investigated because of the potential applications of such ferrite materials in microwave devices. The dielectric and magnetic properties are obtained via the transmission-reflection technique. For Co/sub 2/U, the complex relative /spl epsiv/ and /spl mu/ are obtained from 12.4 GHz-18.0 GHz and for Ni/sub 2/U, the complex relative /spl epsiv/ and /spl mu/ are obtained from 18.0 GHz-40.0 GHz.