HfO2-TiO2-Y2O3 is an interesting high-k dielectric system, with the potential for higher values of k than the end members. Combinatorial library films of this system enable the study of the role of composition on phase formation as well as optical and mechanical properties. A library film of this system deposited at 400 degrees C exhibited a boundary line evident visually as well as in characterization. Mapping X-ray analysis showed the line corresponds to a crystallinity boundary, separating an amorphous phase and a face-centered cubic crystalline phase of yttrium hafnium oxide. Mapping nanoindentation across the boundary also revealed a sharp change in mechanical properties. The combinatorial technique is a powerful tool for high-throughput materials science, and by realizing this particularly unique pulsed laser deposition library film, allows many interesting materials phenomena and properties to be measured. (C) 2008 Elsevier B.V. All rights reserved.