The effect of the melt PbO/B2O3ratio on the Curie temperature of LPE films containing lutetium is described along with data showing the flux effect on the bubble collapse field temperature dependence. A mechanism is proposed to explain the observed data involving the complexing of the rare-earth ions in the melt by B2O3. A correlation is shown between the Curie temperature and lattice parameter of lutetium containing LPE films where certain of the important melt ratios are held constant. The variation of Curie temperature with changing growth temperature is also described. The previously observed Curie temperature dependence on the Fe2O3/Lu2O3ratio is confirmed over a wider range of iron to lutetium ratios. The effect of changing the PbO/B2O3ratio and its effect on flux removal is presented.