Speaker
Description
Analyzing material structure by X-ray diffraction in real time is crucial because it probes physical properties during deformation rather than only after the material has stabilized. To this end, we built two in-situ X-ray diffraction systems that monitor nylon 5,6 fibers and perovskite thin films, respectively. For the fibers, drawing above Tg induces polymer-chain orientation and markedly increases mechanical strength. To observe this process, we developed a heater-integrated X-ray transmission drawing stage. With the fiber axis aligned to the beam, WAXS patterns were collected, and the (004) reflections were analyzed to quantify phase fraction, orientation, and lattice strain. The results show a continuous γ→α structural transition during drawing, followed by additional growth of the α component during unloading and cooling. For the perovskite films, we measured degradation behavior in real time. Reflection-mode measurements in air often fail to secure reliable diffraction signals because the encapsulation cover perturbs the optical path. To overcome this, the perovskite was coated on ~150 μm glass and an equally thin glass was used as a cover to enable transmission. The sample was then sealed under N₂ and monitored with a transmission in-situ setup. GIWAXS tracked lattice-parameter shifts, peak-width changes, and the emergence of PbI₂ diffraction, enabling simultaneous quantification of early-stage degradation, phase segregation, and texture evolution. Leveraging these real-time in-situ methods provides structural information that explains—and helps predict—the physical properties of diverse materials.
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| Best Presentation | No |
