Accession Number : AD0678092

Title :   CRYSTAL CHEMISTRY AND MAGNETIC RESONANCE PROPERTIES OF THE VANADATE GARNETS.

Descriptive Note : Final rept. 15 Sep 66-14 Jul 68,

Corporate Author : RAYTHEON CO WALTHAM MASS RESEARCH DIV

Personal Author(s) : Van Hook,H. J. ; Kohane,T. ; Euler,F. K.

Report Date : OCT 1968

Pagination or Media Count : 104

Abstract : Vanadate garnet compositions in the series (Y(3-2x)Ca2x) (Fe(5-x-y)InyVx)O12 have been prepared as single crystals by the PbO flux method and as high density polycrystalline ceramics. The single crystals were examined by electron microprobe which showed constant indium concentration for 0 = or < y = or < 0.35 but a well-defined zoning effect in calcium-vanadium content for 0 = or < x = or < 1.2. Good agreement was obtained from magnetization, Curie point, and X-ray parameter between single-crystal and corresponding polycrystalline compositions. The magnetocrystalline anisotropy K sub 1 and K sub 2 were determined between 4 degrees and 300 degrees K on 16 single crystals. In polycrystalline vanadate garnets the addition substitution of indium causes a substantial reduction in linewidth (delta H) when microstructural influences (porosity, second phase) are minimized. In dense ceramice delta H can be quantitatively correlated with magnetic anisotropy using recent theories developed by Schlomann. (Author)

Descriptors :   (*GARNET, *MAGNETIC RESONANCE), (*CRYSTAL STRUCTURE, GARNET), MAGNETOSTRICTION, ANISOTROPY, CRYSTAL GROWTH, SINGLE CRYSTALS, MICROSTRUCTURE, MICROWAVE FREQUENCY, YTTRIUM COMPOUNDS, IRON COMPOUNDS, CALCIUM COMPOUNDS, INDIUM COMPOUNDS, VANADATES

Subject Categories : Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE