Paineira is the popular name for several species of the Ceiba genus. (Photo: José Carlos Garcia)
Paineira is a beamline optimized for powder diffraction, single crystal diffraction and spectroscopy techniques and aimed at the structural characterization of polycrystalline materials. The powder diffraction technique is complementary to the micro and nanodiffraction technique of the Carnaúba beamline.
Unlike the microdiffraction technique, in which the determination of the unit cell is straightforward by the diffraction pattern of the micrometric crystals, the powder diffraction is widely used to determine the crystal structure of materials of which obtaining single crystals is difficult, either because they are not stable enough or because they are intrinsically polycrystalline. The most recent experimental techniques and computational methods for data analysis allow the determination of the structure of increasingly more complex materials by powder diffraction. One important application of the Paineira beamline, complementary to the Quati beamline, is the in situ study of formation of new crystallographic phases during the course of chemical reactions, for example, changes in the crystal structure in the reactions between solids and gases or liquids, recurring in the research of new catalysts.
The optics of this beamline is being designed to take advantage of the low emittance of the superbend source and produce a beam with low divergence in the vertical direction. In the horizontal direction it will be more divergent, allowing sufficient statistics of the random orientation of the powder granules, aided by the rotation of the sample in a capillary.
The experimental station dedicated to powder diffraction, already installed and in operation in the UVX synchrotron light source, is fully automated and allows performing experiments in tens and hundreds of samples in a few hours. This type of infrastructure is also very important for the pharmaceutical industry as a reference standard for the identification and quantification of solid forms of drugs, for example, polymorphs, solvents, hydrates, co-crystals and amorphous.