Growth of BiYIG films from MoO3-Containing fluxes.

For LPE growth of BiYIG films MoO3 is shown to be a flux modifier which increases Bi content, x(Bi), and growth-induced anisotropy, K(u)(g), for MoO3 flux concentrations up to 12 Mole% (M%). The addition of MoO3 to PbO-Bi2O3 fluxed garnet melts caused the saturation temperature to increase at a rate of 7 deg/M% while growth rates decreased. For a given amount of supercooling, delta T(s), x(Bi) increased with MoO3 flux content up to 12 M%. A linear dependence of x(Bi) on delta T(s) was observed for all MoO3 concentration levels. The anisotropy increased both with supercooling and with MoO3 flux concentration. K (u)(g) can be represented by a two-variable model, K(u)(g) = A + Bx(Bi) + C 4IIM(s), where B increases from 133 to 200 kerg/cm(3) per Bi atom per formula unit as the MoO3 content of the flux increases from 0 to 12 M%. Corresponding B values for V2O5 flux grown films are lower. However, if anisotropy generation per degree supercooling is compared the two flux systems appear equivalent. Density considerations limit MoO3 content to 15 M%. Partial substitution of Y by Gd and Ho as required for device films reduces the available growth-induced anisotropy by ~15%.