Uniform films of rare-earth-doped zirconia and yttrium aluminum garnet have been deposited from aqueous solutions of stoichiometric mixtures of the precursor metal nitrates to which an organic complexant such as the simple amino acid glycine has been added. The presence of glycine prevents precipitation by trapping metal cations and nitrate anions in the evolving glassy matrix as water evaporates during spin casting of films. Subsequent thermal processing above 200 degrees C generates the target oxide composition. High index films with a nanosize grain morphology result. The resident small crystalline grains aid in stabilizing a particular phase of the oxide. The presence of the Sm3+ dopant in the films facilitates phase identification through analysis of the fluorescence emission spectrum. This technique complements X-ray diffraction and Raman spectroscopy measurements which are used routinely to identify crystalline phases and evaluate phase homogeneity in optical films. The fluorescence measurement technique is a rapid non-destructive approach for investigating the influence of processing variables on the resulting crystalline phase and phase stability during subsequent annealing.