Accession Number : AD0282616

Title :   RESEARCH AND DEVELOPMENT OF YTTRIUM IRON GARNET SINGLE CRYSTALS

Corporate Author : TEXAS INSTRUMENTS INC DALLAS

Report Date : 02 JUL 1962

Pagination or Media Count : 1

Abstract : Major emphasis was on refining the floating-zone technique to produce single crystal yttrium iron garnets at least 1/2 in. in diameter and 1 in. long with a ferrimagnetic resonance line-width in the X-band frequency range of less than 1 oersted. Yttrium iron garnet (YIG) single crystals 1/4 to 3/8 in. diam with a dielectric constant of about 10 and dissipation factor of 0.002AT 1000 C WERE PRODUCED BY THIS TECHNIQUE. Ferrimagnetic resonance line-widths at X-band of 1.3 oersteds were obtained from polished test spheres. A technique was developed by which several float-zoned specimens were produced with crack-free cross sections. The identity, origin, and means for prevention of a second phase in YIG is discussed. The second phase, a mixture of iron oxide and YIG, was prevented from forming with improved temperature control and slower zoning rates (0.1 in./hr or less). Data are presented from resonance line-width (delta H) measurements at X-band and at C-band. Preliminary results from heat treating exp riments indicate that the delta H of YIG test spheres can be reduc by annealing. A improved technique is described for rapid polishing of YIG spheres. Results of chemical and electrical evaluations of float-zoned YIG are discussed. (Author)

Descriptors :   *GARNET, *SINGLE CRYSTALS, ELECTRON MICROSCOPY, FERROMAGNETIC MATERIALS, GROWTH(PHYSIOLOGY), IRON COMPOUNDS, SPECTROGRAPHIC ANALYSIS, X BAND, X RAY DIFFRACTION, YTTRIUM COMPOUNDS

Distribution Statement : APPROVED FOR PUBLIC RELEASE