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Structural behaviour of cyclo-octane under high pressure is studied by using a synchrotron x-ray source in a diamond anvil cell (DAC) up to 40.2 GPa at room temperature. The cyclo-octane firstly solidifies to the triclinic phase at 0.87 GPa. With the increasing pressure, the phase of cyclo-octane changes to the tetragonal phase at about 6.0 GPa and then transforms to amorphous phase above 18.2 GPa, which is kept till to 40.2 GPa. All the phase transitions of cyclo-octane are irreversible. 相似文献
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High-Pressure Phase Transitions of Cubic Y_2O_3 under High Pressures by In-situ Synchrotron X-Ray Diffraction 下载免费PDF全文
High-pressure phase transitions of cubic Y_2O_3 are investigated using in situ synchrotron x-ray diffraction in a diamond anvil cell up to 36.3 GPa. The pressure-induced phase transitions of cubic Y_2O_3, which display apparent inconsistencies in previous studies, are verified to be from a cubic phase to a monoclinic phase and further to a hexagonal phase at 11.7 and 21.6 GPa, respectively. The hexagonal Y_2O_3 displays noticeable anisotropic compressibility due to its layered structure and it is stable up to the highest pressure in the present study. A third-order Birch–Murnaghan fit based on the observed pressure-volume data yields zero pressure bulk moduli of180(3), 196(7) and 177(7) GPa for cubic, monoclinic and hexagonal phases, respectively. 相似文献
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应用原位能量色散X射线散射和金刚石对顶砧技术,对纳米晶ZnS进行了高压结构相变研究。初始相为纤锌矿结构的10 nm和3 nm硫化锌分别在16.0 GPa和16.7 GPa时转变为岩盐矿结构,相变压力均高于纤锌矿结构的体材料硫化锌。该相变为一可逆的结构相变。应用大型科学计算软件Materials Studio(MS)计算了纳米晶ZnS的状态方程,根据Birch-Murnaghan方程拟合了纳米晶ZnS的零压体模量,得到的零压体模量高于相应体材料的零压体模量,表明纳米晶ZnS较难压缩。 相似文献
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Phase Transition of Graphitic-C3N4 under High Pressure by In Situ Resistance Measurement in a Diamond Anvil Cell 下载免费PDF全文
In situ resistance measurement of Graphitic-C3N4 has been performed under high pressure in a diamond anvil cell. The result reveals that there are changes of electron transport behaviour. As the pressure increases from ambient to 30 GPa, three abnormal resistance changes can be found at room temperature and two are found at 77K. The abnormal resistance dropped at 5 GPa is close to the phase transition pressure from the P6m2 structure to the p structure predicted by Lowther et al. [Phys. Reg. B 59 (1999) 11683] Another abnormal change of resistance at 12 GPa is related to the phase transition from g-C3N4 to cubic-C3N4 [Teter and Hemley, Science 271 (1990) 53]. 相似文献
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The static equation of state (EOS) of tantalum (Ta) is determined by in situ energy-dispersive synchrotron powder x-ray diffraction in a diamond anvil cell (DAC) up to 133GPa. The body-centered-cubic (bcc) phase of Ta is found to be stable over the entire pressure range investigated. The bulk moduli and its first pressure derivative of Ta are constrained by fitting the determined pressure-volume data to Vinet form EOS: B0 =192.65±(3.08)GPa and B'0 =3.58±(0.11). For the sake of avoiding the affect of non-hydrostatic stress, argon is used as a pressure media. A careful checking of the stress state of the sample is presented simultaneously. 相似文献
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The polyoxometalate K6H[CoW11O39(CpTi)] (abbreviated as CoW11CpTi, Cp=η^5-C5H5) loaded nanosize-liposome complex has been prepared and structurally characterized by elemental analysis, IR and UV spectra. The particle size of the complex was distributed in the range of 100-250 nm with the average diameter of 132.6 nm. The result showed that the polyoxometalate retained the parent structure after being encapsulated by liposome and liposomal encapsulation increased the antitumoral activity of the polyoxometalate. 相似文献