A new technique has been developed for direct measurement of the differential X-ray absorption fine structure（XAFS） spectrum by the energy-modulation method. To acquire the energy-oscillating incident X-ray beam, a ...A new technique has been developed for direct measurement of the differential X-ray absorption fine structure（XAFS） spectrum by the energy-modulation method. To acquire the energy-oscillating incident X-ray beam, a piezoelectric actuator is used to control the double-crystal monochromator. A logarithmic converter circuit and a lock-in amplifier are used to extract the modulated signals. The normal and differential XAFS spectra of the Mn K-edge of Li2 Mn O3 have been collected. The X-ray-absorption near-edge-structure（XANES） spectra verify that the signal-to-noise ratio has been greatly improved by the new technique, and the extended X-ray absorption fine structure（EXAFS） spectra demonstrate that this new technique can efficiently enhance the signals of the backscattering atoms.展开更多
文摘A new technique has been developed for direct measurement of the differential X-ray absorption fine structure（XAFS） spectrum by the energy-modulation method. To acquire the energy-oscillating incident X-ray beam, a piezoelectric actuator is used to control the double-crystal monochromator. A logarithmic converter circuit and a lock-in amplifier are used to extract the modulated signals. The normal and differential XAFS spectra of the Mn K-edge of Li2 Mn O3 have been collected. The X-ray-absorption near-edge-structure（XANES） spectra verify that the signal-to-noise ratio has been greatly improved by the new technique, and the extended X-ray absorption fine structure（EXAFS） spectra demonstrate that this new technique can efficiently enhance the signals of the backscattering atoms.
