Accession Number : ADA115998

Title :   Epitaxial Garnets and Hexagonal Ferrites.

Descriptive Note : Final technical rept. 1 Feb 80-31 Mar 82.


Personal Author(s) : Glass,H L ; Adkins,L R

PDF Url : ADA115998

Report Date : 20 Apr 1982

Pagination or Media Count : 8

Abstract : The objective of this research is to develop new and improved epitaxial ferrite materials for use in microwave and millimeter-wave signal processing devices. The major emphasis has been on multiple layer magnetic garnet structures for magnetostatic wave (MSW) delay lines. Theoretical analysis and experiments were performed on propagation of magnetostatic surface waves (MSSW), magnetostatic forward volume waves (MSFVW) and magnetostatic backward volume waves (MSBVW) in structures containing up to four layers. In the experiments, one layer was a standard stripline substrate, 10 mil thick alumina. The other layers were YIG (yttrium iron garnet) films grown by liquid phase epitaxy (LPE) on gadolinium gallium garnet (GGG) substrates. Magnetic properties of the YIG layers were adjusted by modifying their chemical composition. Delay characteristics were measured in detail at frequencies between 2 and 4 GHz. Using MSSW, a multilayer structure having a flatter nondispersive delay than conventional single layer devices was demonstrated. Linear dispersion similar to that of conventional single layer devices but easier to implement was demonstrated for MSFVW propagation in a structure containing three epitaxial layers. In addition to the MSW work on garnets, LPE of lithium ferrite and hexagonal ferrites was studied. A substituted lead hexaferrite which exhibited 50 GHz resonance in a field on only 3 KOe was demonstrated. (Author)

Descriptors :   *Garnet, *Yttrium iron garnet, *Ferrites, *Epitaxial growth, Crystal growth, Microwave equipment, Millimeter waves, Signal processing, Surface waves, Wave propagation, Magnetostatics, Ferromagnetic resonance, Liquid phases, Aluminum oxides, Gadolinium compounds, Gallium, Lithium compounds, Delay lines, Layers

Subject Categories : Geology, Geochemistry and Mineralogy

Distribution Statement : APPROVED FOR PUBLIC RELEASE