2001年2月23日 · The structure of La 2 @C 80 is studied by La K-edge XAFS from 40 to 295 K. The distances between the La atom and the first nearest C atoms have been determined to be 2.42(1) Å at 40 K and 2.44(2) Å at 295 K, and those between the La atom and the second nearest C atoms to be 2.97(2) Å at 40 K and 2.98(3) Å at 295 K.

The values for f' and f" are derived using the theoretical approximation developed by Cromer and Liberman. This theory gives accurate values far from an absorption edge but does not account for the effects of neighboring atoms, which can be very substantial near an absorption edge.

In the present study, we recorded La K-edge XAFS spectra to examine the structure of La species on alumina and their structural transformation upon thermal treatment.

2001年8月22日 · La / Al2O3催化剂材料的结构分析是通过XRD和La K-edge XAFS进行的。 研究了负载量和处理温度对La周围局部结构的影响。 当负载量小于0.2 mmol g（Al2O3）（-1）时，La原子以高度分散的形式负载在γ-Al2O3上，并且在873-1273的温度范围内不会发生La物种的结构转变K.高负荷催化剂中的La物种在1073 K时开始从其氧化物形式转变为铝酸盐结构。 在催化剂表面形成LaAlO3钙钛矿需要浓度高于0.5 mmol g（Al2O3）（-1）的La原子（7.5重量％为La 2 O …

The results indicated that La promoted the activity of Pd/La-Al 2 O 3 catalyst for NO-CO reaction. ... Key role of NO + C3H8 reaction for the elimination of NO in automobile exhaust by...

2017年11月6日 · La K-edge X-ray absorption spectroscopy has been used to elucidate the changes in the local electronic and lattice structure that occur in the A-site deficient double perovskite La 1 / 3 NbO 3 up to 6 GPa. The pressure evolution of the oxygen dodecahedrum around the A-site has been examined.

This review gives an overview of the application of metal K-edge and L-edge X-ray absorption spectroscopy (XAS), as well as K resonant inelastic X-ray scattering (RIXS), to the study of electronic structure in transition metal sites with emphasis on …

2004年7月1日 · Structural analysis of La/Al2O3 catalyst materials was carried out by means of XRD and La K-edge XAFS. Influences of loading amounts and treatment temperature on the local structure around La were ...

2002年10月23日 · The local structure of molten LaCl 3 was investigated by X-ray absorption fine structure of the La K-edge. The nearest La 3+ –Cl − distance and coordination number were 2.89±0.01 Å and 7.4±0.5 from the curve fitting of the first peak in …

2023年11月3日 · K-edge（K边缘） 是X射线吸收光谱中的一个特定能量点。 这个点与原子核的K壳层（内壳层）电子有关。 当入射X射线的能量等于或略高于K壳层电子的束缚能量时，会发生K-edge吸收。