Electronic structure of KD2xH2(1-x)PO4 studied by soft x-ray absorption and emission spectroscopies
Electronic structure of KD2xH2(1-x)PO4 studied by soft x-ray absorption and emission spectroscopies
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DOI：
10.1103/physrevb.70.245106
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发表时间：
2004-04
影响因子：
3.7
通讯作者：
S. Kucheyev;C. Bostedt;T. Buuren;T. Willey;T. Land;L. Terminello;T. Felter;A. Hamza;S. Demos;A. Nelson
中科院分区：
文献类型：
--
作者：
S. Kucheyev;C. Bostedt;T. Buuren;T. Willey;T. Land;L. Terminello;T. Felter;A. Hamza;S. Demos;A. Nelson
The surface and bulk electronic structure of tetragonal (at 300 K) and orthorhombic (at 77 K) KD{sub 2x}H{sub 2(1-x)}PO{sub 4} single crystals (so-called KDP and DKDP), with a deuteration degree x of 0.0, 0.3, and 0.6, is studied by soft x-ray absorption near-edge structure (XANES) and non-resonant soft x-ray emission (XES) spectroscopies. High-resolution O K-edge, P L{sub 2,3}-edge, and K L{sub 2,3}-edge XANES and XES spectra reveal that the element-specific partial density of states in the conduction and valence bands is essentially independent of deuteration x. We give assignment of XANES and XES peaks based on previous molecular orbital and band-structure calculations. Projected densities of states in the conduction band also appear to be essentially identical for tetragonal (at 300 K) and orthorhombic (at 77 K) phases, consistent with previous band structure calculations. However, a decrease in sample temperature from 300 to 77 K results in an {approx} 0.5 eV shift in the valence band edge (probed by XES), with negligible changes to the conduction band edge (probed by XANES). Results also show that high-intensity x-ray irradiation results in decomposition of these hydrogen-bonded materials into water and KPO{sub 3} cyclo- and polyphosphates.
