Growth of BiYIG films from MoO₃–containing fluxes

Abstract

For liquid phase epitaxial (LPE) growth of BiYIG films, MoO₃ is shown to be a flux modifier that increases Bi content x_Bi, and growth-induced anisotropy K_u⁸, for MoO₃ flux concentrations up to 12 mol %. The addition of MoO₃ to PbO–Bi₂O₃ fluxed garnet melts caused the saturation temperature to increase at a rate of 7 deg/mol % while growth rates decreased. For a given amount of supercooling, ΔT_s, x_Bi increased with MoO₃ flux content up to 12 mol %. A linear dependence of x_Bi on ΔT_s, was observed for all MoO₃ concentration levels. The anisotropy increased both with supercooling and with MoO₃ flux concentration. The K^g_u can be represented by a two-variable model, K^g_u = A +Bx_Bi + C4IIM_s, where B increases from 143–213 kerg/cm³ per Bi atom per formula unit as the MoO₃ content of the flux increases from 0–12 mol %. The density of the melt decreases with increased MoO₃ content. A melt based on a 15 mol % MoO₃ flux is less dense than gadolinium gallium garnet.