Pure-Yttrium iron garnet (Y3Fe5O12; YIG) films were grown from a MoO3-Li2O flux onto (1 1 1) GGG substrate using liquid phase epitaxy. By investigating the [Fe2O3]/[Y2O3] molar ratio of the flux, we were able to successfully grow stoichiometric and high-purity YIG films. Evaluations and calculations of lattice mismatch along the <1 1 1>, <0 0 1>, and <1 1 0> directions using X-ray rocking-curve measurements revealed that these values differed significantly from one another. This clearly indicated that structural deformation had occurred in the YIG films. The deformation was larger in the films grown from the MoO3-Li2O flux than in those grown from a PbO-B2O3 flux. However, the impurity concentration in the former was one hundred times less than that in the latter. Thus, because of this purity, the YIG films grown from the MoO3-Li2O fluxes are preferable for use in optical and microwave devices. (C) 2002 Elsevier Science B.V. All rights reserved.