C60·2CHBr3 polycrystalline powder was prepared by the solution method. The vibrational modes of the sample were studied by Raman scattering and infrared adsorption techniques. The Raman spectra showed that the Ag...C60·2CHBr3 polycrystalline powder was prepared by the solution method. The vibrational modes of the sample were studied by Raman scattering and infrared adsorption techniques. The Raman spectra showed that the Ag modes were downshifted by 4-5 cm1, while the Hg(1) mode was unshifted. The analyses of the downshifts of the Ag modes revealed that a small amount of electrons were transferred from the hydrogen atoms to the C60 molecules. In the infrared spectra, the F1u modes of the pristine C60 were unshifted after the intercalation with CHBr3. However, the vibrational modes of CHBr3 changed remarkably. The C-Br stretching mode was downshifted by ～4 cm1. The adsorption of the C-H twisting mode was weakened obviously, and the adsorption of the C-H stretching mode was not observed. These results exhibited that there were nonnegligible interactions between CHBr3 and C60 molecules, and that the strongest interaction took place between the hydrogen atoms and the C60 molecules. The interaction should induce not only the changes of the vibrational modes reported here, but also those of the electronic states. So this work should offer important glues to the mechanism of the superconductivity at 117 K of the field-doped C60·2CHBr3.展开更多
The perovskite-like structure compound Ca0.85- CuO2 has interesting structural properties: it has infinite one-dimensional edge-sharing copper-oxygen chains as well as partial occupancy of the Ca sites resulting in an...The perovskite-like structure compound Ca0.85- CuO2 has interesting structural properties: it has infinite one-dimensional edge-sharing copper-oxygen chains as well as partial occupancy of the Ca sites resulting in an incom-mensurate superstructure. In situ high-pressure energy dis-persive X-ray diffraction measurements on polycrystalline powder Ca0.85CuO2 have been performed by using diamond anvil cell (DAC) instrument with synchrotron radiation. The results for the first time show that edge-sharing copper oxide Ca0.85CuO2 undergoes a structural transition at 14.5 GPa, and furthermore the structural transition is reversible.展开更多
In situ high-pressure energy dispersive X-ray diffraction measurements on polycrystalline powder CaCuO2 with an infinite layer structure (IL CaCuO2) have been performed by using diamond anvil cell (DAC) instrument wit...In situ high-pressure energy dispersive X-ray diffraction measurements on polycrystalline powder CaCuO2 with an infinite layer structure (IL CaCuO2) have been performed by using diamond anvil cell (DAC) instrument with synchrotron radiation. The results suggest that the crystal structure of IL CaCuO2 is stable under pressure up to 30 GPa at room temperature. According to Birch-Murn- aghan equation of state, assuming pressure derivative the bulk modulus B0=181 ± 9 GPa is obtained.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.10074053)the Natural Science Foundation of Zhejiang Province(Grant No.100019).
文摘C60·2CHBr3 polycrystalline powder was prepared by the solution method. The vibrational modes of the sample were studied by Raman scattering and infrared adsorption techniques. The Raman spectra showed that the Ag modes were downshifted by 4-5 cm1, while the Hg(1) mode was unshifted. The analyses of the downshifts of the Ag modes revealed that a small amount of electrons were transferred from the hydrogen atoms to the C60 molecules. In the infrared spectra, the F1u modes of the pristine C60 were unshifted after the intercalation with CHBr3. However, the vibrational modes of CHBr3 changed remarkably. The C-Br stretching mode was downshifted by ～4 cm1. The adsorption of the C-H twisting mode was weakened obviously, and the adsorption of the C-H stretching mode was not observed. These results exhibited that there were nonnegligible interactions between CHBr3 and C60 molecules, and that the strongest interaction took place between the hydrogen atoms and the C60 molecules. The interaction should induce not only the changes of the vibrational modes reported here, but also those of the electronic states. So this work should offer important glues to the mechanism of the superconductivity at 117 K of the field-doped C60·2CHBr3.
文摘The perovskite-like structure compound Ca0.85- CuO2 has interesting structural properties: it has infinite one-dimensional edge-sharing copper-oxygen chains as well as partial occupancy of the Ca sites resulting in an incom-mensurate superstructure. In situ high-pressure energy dis-persive X-ray diffraction measurements on polycrystalline powder Ca0.85CuO2 have been performed by using diamond anvil cell (DAC) instrument with synchrotron radiation. The results for the first time show that edge-sharing copper oxide Ca0.85CuO2 undergoes a structural transition at 14.5 GPa, and furthermore the structural transition is reversible.
文摘In situ high-pressure energy dispersive X-ray diffraction measurements on polycrystalline powder CaCuO2 with an infinite layer structure (IL CaCuO2) have been performed by using diamond anvil cell (DAC) instrument with synchrotron radiation. The results suggest that the crystal structure of IL CaCuO2 is stable under pressure up to 30 GPa at room temperature. According to Birch-Murn- aghan equation of state, assuming pressure derivative the bulk modulus B0=181 ± 9 GPa is obtained.
