9302173 Gladfelter At the core of all materials research is the need to know composition and structure. These determine the physical properties and may reflect the synthesis and processing history of the materials. Rutherford backscattering (RBS) and forward recoil spectrometry (FRES) are two powerful tools for establishing the compositions and depth profiles of thin films. Several programs at the University of Minnesota will make use of this RBS System, including a) using RBS to evaluate diffusion processes in olivine that may contribute to movement of material in the earth's mantle, b) using RBS to characterize compositions of high temperature superconducting metal oxide films c) using RBS to characterize chemical reactions that occur at interfaces and control the fracture mechanics of the films, d) using FRES to quantify the hydrogen (or deuterium) content of films grown from organometallic precursors, e) using FRES to study diffusion of polymers. ***