L2,3 X-RAY-ABSORPTION EDGES OF D0 COMPOUNDS - K+, CA-2+, SC-3+ AND TI-4+ IN OH (OCTAHEDRAL) SYMMETRY
L2,3 X-RAY-ABSORPTION EDGES OF D0 COMPOUNDS - K+, CA-2+, SC-3+ AND TI-4+ IN OH (OCTAHEDRAL) SYMMETRY
复制标题
DOI：
10.1103/physrevb.41.928
复制
发表时间：
1990-01-15
影响因子：
3.7
通讯作者：
SAWATZKY, GA
中科院分区：
文献类型：
--
作者：
DEGROOT, FMF;FUGGLE, JC;SAWATZKY, GA
的L2，3的X射线吸收边的3 D 0化合物的计算与使用的原子描述的2 p 6 3 D 0到2 p 5 3 D 1激发，与列入的晶体场。为了清楚起见，我们只限于d 0化合物在八面体对称，但同样的方法是适用于所有其他dN化合物在任何点群对称。计算结果很好地再现了FeTiO 3，Sc2 O 3，ScF 3，CaF 2和卤化钾的实验光谱，包括以前被误解的小的前导峰。在L3和L2边缘的两个主峰之间的分裂与晶场分裂有关，但不相等。与实验结果比较表明，主要多重峰线的展宽是不同的。这可能与科斯特-克罗尼希俄歇过程的L 2边缘和固态加宽，这是一个振动（声子）和色散加宽的组合。通过对原子多重态的充分处理，可以将原子效应与固态效应分开，从而更好地描述固态效应。这包括振动加宽，共价屏蔽的原子内库仑和交换相互作用，通过小的领先峰的位置，和表面效应。相同的一般框架可以用来讨论晶体场效应在两个较低的对称性，与偏振相关的光谱的可能性（例如，TiO 2），和部分填充的d带。
The L 2, 3 x-ray-absorption edges of 3 d 0 compounds are calculated with use of an atomic description of the 2 p 6 3 d 0 to 2 p 5 3 d 1 excitation, with the inclusion of the crystal field. For reasons of clarity, we confine ourselves to d 0 compounds in octahedral symmetry, but the same approach is applicable to all other d N compounds in any point-group symmetry. The experimental spectra of FeTiO 3, Sc 2 O 3, ScF 3, CaF 2, and the potassium halides are well reproduced by the present calculations, including the previously misinterpreted small leading peaks. The splitting between the two main peaks in both the L 3 and L 2 edge are related, though not equal, to the crystal-field splitting. Comparison to experiment showed that the broadening of the main multiplet lines is different. This can be related to Coster-Kronig Auger processes for the L 2 edge and to a solid-state broadening which is a combination of vibrational (phononic) and dispersional broadenings. With the full treatment of the atomic multiplets, the atomic effects can be separated from solid-state effects, which offers a better description of the latter. This includes vibrational broadenings, the covalent screening of the intra-atomic Coulomb and exchange interactions, via the position of small leading peaks, and surface effects. The same general framework can be used to discuss crystal-field effects in both lower symmetries, with the possibility of polarization-dependent spectra (eg, TiO 2), and partly filled d bands.