Thin film piezoelectric materials have many applications, including in high frequency bulk acoustic wave resonators. However, conventional thin film materials such as AlN have quite poor piezoelectric properties. Research involving bulk piezoelectric material has now produced widely available single crystals such as (1-x)Pb(Mg1/3,Nb2/3)O3-x(PbTiO3) (PMN-PT) which offer much higher performance, and thin films of such materials are also viable. In this paper, work on sputtered AlN and pulsed laser deposited PMN-PT thin films is described, including measurements of Ag/AlN/Al trilayers on several different substrates and Au/PMNPT/La0.5Sr0.5CoO3 trilayers on single crystal MgO. Analysis via the spacing of parallel resonant frequencies in electrical impedance and Sparameter measurements has also been explored. This technique takes into account that the films are not self-supported and that their properties are dependent on the substrate. Using various software tools most often applied to bulk materials, with appropriate material parameters, further exploration of the suitability of PMN-PT for thin film device fabrication and direct comparison with AlN have been considered.