Applications of an amorphous silicon-based area detector for high-resolution, high-sensitivity and fast time-resolved pair distribution function measurements

The application of a large-area (41 × 41 cm, 2048 × 2048 or 1024 × 1024 pixel) high-sensitivity (detective quantum efficiency > 65%) fast-readout (up to 7.5 or 30 Hz) flat-panel detector based on an amorphous silicon array system to the collection of high-energy X-ray scattering data for quantitative pair distribution function (PDF) analysis is evaluated and discussed. Data were collected over a range of exposure times (0.13 s-7 min) for benchmark PDF samples: crystalline nickel metal and amorphous silica (SiO2). The high real-space resolution of the resultant PDFs (with Q max up to ∼40 Å^-1) and the high quality of fits to data [R _Ni(0.13s) = 10.5%, R_Ni(1.3s) = 6.3%] obtained in short measurement times indicate that this detector is well suited to studies of materials disorder. Further applications of the detector to locate weakly scattering H2 molecules within the porous Prussian blue system, Mn ₃^II[Co^III(CN)₆]₂· xH₂, and to follow the in situ reduction of Pt^IVO ₂ to Pt⁰ at 30 Hz, confirm the high sensitivity of the detector and demonstrate a new potential for fast time-resolved studies.