The atomic structure of a novel rare earth complex consisting of Nd and the sulfur-containing ligand pipdtc (C5H10NCS-2) has been studied with extended x-ray absorption fine structure (EXAFS} and x-ray diffraction tec...The atomic structure of a novel rare earth complex consisting of Nd and the sulfur-containing ligand pipdtc (C5H10NCS-2) has been studied with extended x-ray absorption fine structure (EXAFS} and x-ray diffraction techniques. The complex of formula Nd(pipdtc)4N(CH3)4 crystallizes in the monoclinic space group P21/n with the following lattice parameters, a = 22.685(2), b = 20.332(2), c = 17.1270(10)Å, β = 100.570(10)o, Z = 8. The calculated density is 1.47g/cm3. A new derivative method is used to remove the post-edge absorption background including the multielectron excitation effect. The EXAFS results demonstrate that there are about eight S and four O atoms around Nd with the Nd-S bond length of 2.916Å and the Nd-O bond length of 2.415Å, respectively. This implies that the powder of this complex is not stable and is easy to oxidize in air. The possible change of structure before and after oxidation is discussed.展开更多
Many modulation techniques have been widely applied to improve the quality of conventional spectra. Here a pressure-modulated EXAFS method is proposed to detect the small changes of local structure induced by the modu...Many modulation techniques have been widely applied to improve the quality of conventional spectra. Here a pressure-modulated EXAFS method is proposed to detect the small changes of local structure induced by the modulation of high pressure. In the experiment a dynamic diamond anvil cell was used to put a periodic load on the sample and lock-in amplifier to measure the modulated EXAFS signals. We have applied this technique to ZnSe and revealed a sensitivity to atomic displacement of 0.1 pm that is about ten times better than that of traditional EXAFS.展开更多
基金the Foundations of the Chinese Academy of Sciences and the Chinese Ministry of Education for returned scholars back from abroad,the Doctoral Program Foundation of Higher Education in China under Grant No.95968the Postdoctoral Foundation of Chinese Academy of Sciences.
文摘The atomic structure of a novel rare earth complex consisting of Nd and the sulfur-containing ligand pipdtc (C5H10NCS-2) has been studied with extended x-ray absorption fine structure (EXAFS} and x-ray diffraction techniques. The complex of formula Nd(pipdtc)4N(CH3)4 crystallizes in the monoclinic space group P21/n with the following lattice parameters, a = 22.685(2), b = 20.332(2), c = 17.1270(10)Å, β = 100.570(10)o, Z = 8. The calculated density is 1.47g/cm3. A new derivative method is used to remove the post-edge absorption background including the multielectron excitation effect. The EXAFS results demonstrate that there are about eight S and four O atoms around Nd with the Nd-S bond length of 2.916Å and the Nd-O bond length of 2.415Å, respectively. This implies that the powder of this complex is not stable and is easy to oxidize in air. The possible change of structure before and after oxidation is discussed.
基金Supported by National Natural Science Foundation of China (10875143)
文摘Many modulation techniques have been widely applied to improve the quality of conventional spectra. Here a pressure-modulated EXAFS method is proposed to detect the small changes of local structure induced by the modulation of high pressure. In the experiment a dynamic diamond anvil cell was used to put a periodic load on the sample and lock-in amplifier to measure the modulated EXAFS signals. We have applied this technique to ZnSe and revealed a sensitivity to atomic displacement of 0.1 pm that is about ten times better than that of traditional EXAFS.
