Previously, we have shown that temperature gradients can be smoothed, and thermocapillary convection suppressed, in a model half-zone of silicone oil and also in a float-zone of sodium nitrate, by inducing an opposing surface streaming flow through vibration of one of the supporting end-walls. In this work we demonstrate the effect of vibration in promoting uniform microstructures during the float-zoning of NaNO3-Ba(NO3)2 eutectic ''alloys.''