摘要
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.
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.
基金
Supported by NSFC(11175202)
