Phase transition of KDP observed by Resonant X-ray Diffraction at forbidden reflections
نویسندگان
چکیده
We report observations of space-group-forbidden Bragg re ections in Potassium Dihydrogen Phosphate (KH2PO4), also known as KDP, measured by resonant x-ray di raction at the potassium K edge. We nd clear evidence for a transition from one class of space-groupforbidden re ections, where scattering is ruled out by the electric dipole approximation, to a second class, in the ferroelectric phase, where scattering can proceed due to resonant anisotropy within the dipole approximation. The change of symmetry is clearly evidenced by the sudden change of intensity and energy spectrum of the forbidden re ections.
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تاریخ انتشار 2017