Synchrotron x-ray microbeam diagnostics of combinatorial synthesis

X-ray microbeam techniques (spot size = 3 x 20 mu m(2)) have been applied to characterize the composition and structure of rare earth activated Gd(La, Sr) AlO3 phosphor thin films grown by combinatorial synthesis. Using x-ray fluorescence, x-ray diffraction and near-edge x-ray absorption spectroscopy, we have measured the chemical composition, crystallographic structure, and valence state of the rare earth activator atom Eu. These measurements represent the direct application of x-ray techniques to solid-state materials prepared by combinatorial synthesis and demonstrate the power of x-ray microbeam analysis to nondestructively characterize as-grown combinatorial libraries. (C) 1998 American Institute of Physics. [S0003-6951(98)03239-2].