CRYSTAL CHEMISTRY AND MAGNETIC RESONANCE PROPERTIES OF THE VANADATE GARNETS.

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)