Accession Number : ADA260483


Title :   Hexagonal Ferrites for Millimeter Wave Applications


Descriptive Note : Final rept. 1 Jun 1987-31 May 1990


Corporate Author : COLORADO STATE UNIV FORT COLLINS DEPT OF PHYSICS


Personal Author(s) : Polk, Donald E. ; Hathaway, Kristl B. ; Patton, Carl E.


Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=ADA260483


Report Date : 07 JAN 1993


Pagination or Media Count : 8


Abstract : This final report presents a review of the work accomplished on this contract. A review of the physics of hexagonal ferrite materials and the effective linewidth concept and the detailed overall research plan are contained in the original proposal document. The focus of the program was on the effective linewidth in millimeter wave materials, including planar hexagonal ferrite Y- type materials, uniaxial M-type materials, and thin ferromagnetic transition metal and alloy films. The key idea in the original proposal was that the ferromagnetic resonance linewidth in hexagonal ferrites is dominated by inhomogeneous and two-magnon scattering losses and that off-resonance measurements of the effective linewidth would (1) show that the FMR losses do not represent the intrinsic losses and (2) that the intrinsic losses are significantly lower. This basic idea was verified. Results were obtained on the off-resonance far-field effective linewidth in planar Zn-Y hexagonal ferrite single crystal platelets, single crystal spheres of Ba- and Sr-hexaferrite materials, and permalloy thin films. Three papers on these results have been published.


Descriptors :   *MILLIMETER WAVE EQUIPMENT , *FERRITES , *FERROMAGNETIC RESONANCE , METALS , SCATTERING , TRANSITION METALS , MAGNETIC ALLOYS , MATERIALS , THIN FILMS , SINGLE CRYSTALS , FAR FIELD , FERROMAGNETIC MATERIALS


Subject Categories : PROPERTIES OF METALS AND ALLOYS
      ELECTRICITY AND MAGNETISM


Distribution Statement : APPROVED FOR PUBLIC RELEASE