EFFECT OF GROWTH ATMOSPHERE ON RARE-EARTH IRON GARNETS GROWN FROM PBO-BASED FLUXES

The growth atmosphere over a PbO fluxed melt can significantly affect the platinum and lead concentrations and the magnetic properties of rare-earth iron garnet films grown from that melt. We have investigated this effect using the simple composition (Gd//2//. //5Eu//0//. //5Fe//5O//1//2. The films were grown in N//2, air, and O//2 atmosphere. The incorporation of lead and platinum increased the lattice parameter and the index of refraction of these garnets. The diamagnetic octahedral substitution of Pt had a predictable effect on the magnetic properties, increasing the saturation magnetization and decreasing the Curie temperature, cubic anisotropy, and gyromagnetic ratio. Least-squares analysis and annealing studies showed that lead makes a positive contribution to the growth-induced anisotropy that seems to depend only on the concentration of the Pb**2** plus species. Platinum incorporation causes a negative contribution to the growth-induced anisotropy that can be annealed out at temperatures of 850-950 degree C.