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The equation of state (EOS) of mixture of Li 1. 2 Mn 0. 5 4 Co 0. 1 3 Ni 0. 1 3 O2 and LiNi 0. 8 7 Co 0. 0 9 Mn 0. 0 3 Al 0. 0 1 O2 was studied by synchrotron radiation X-ray diffraction (XRD) at room-temperature in a diamond anvil cell (DAC). The results showed that the hexagonal structure is maintained to the highest pressure of 23.1 GPa. The bulk modulus and its first derivative obtained from XRD data are K 0 = 1 4 7. 4 (3. 1)  GPa and K 0 ′ = 2. 2 1 (0. 3 3) , respectively. In addition, we have investigated the high-pressure electrical conductivity of the mixture of Li 1. 2 Mn 0. 5 4 Co 0. 1 3 Ni 0. 1 3 O2 and LiNi 0. 8 7 Co 0. 0 9 Mn 0. 0 3 Al 0. 0 1 O2 to 22.9 GPa in a DAC. It is found that the resistance decreases with the increase of pressure and changes exponentially. [ABSTRACT FROM AUTHOR]

The structure and properties of the nanosized CeO 2 under high pressure have been investigated by synchrotron X-ray diffraction in the diamond anvil cell combined with the first-principle methods based on density functional theory. The experimental data demonstrate that nanosized CeO 2 is highly stable upto 31.3 GPa and bulk modulus is 2 1 3 ± 3  GPa. The calculated results by LDA + U indicate that CeO 2 undergoes structural transition from cubic fluorite-type structure to orthorhombic α - PbCl 2 -type structure at 20 GPa. The indirect band gap (R → G) is 1.89 eV and increases with the increasing pressure while it suddenly reduces to 1.62 eV at transition pressure. The transition pressure calculated by GGA is 40.3 GPa. [ABSTRACT FROM AUTHOR]