Epitaxial thin films of TmFeCuO4 with a two-dimensional triangular lattice structure were successfully grown on yttria-stabilized-zirconia substrates by pulsed laser deposition and ex situ annealing in air. The films as-deposited below 500 degrees C showed no TmFeCuO4 phase and the subsequent annealing resulted in the decomposition of film components. On the other hand, as-grown films deposited at 800 degrees C showed an amorphous nature. Thermal annealing converted the amorphous films into highly (0 0 1)-oriented epitaxial films. The results of scanning electron microscopic analysis suggest that the crystal growth process during thermal annealing is dominated by the regrowth of non-uniformly shaped islands to the distinct uniform islands of hexagonal base. (C) 2010 Elsevier B.V. All rights reserved.