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The phase diagram of the CuInSe2-CuGaSe2 pseudobinary system was determined using a combination of special quasirandom structure approach, ab initio density functional theory calculations, and thermodynamic modelling. It is shown that the CuIn1–xGaxSe2 solution phase has a tendency to phase separation at low temperature. The calculated consolute temperature is 485 K. It is found that both the binodal and spinodal curves are significantly asymmetric and on both curves there are a local maximum and a local minimum, which have not been reported in the previous studies. Our phase diagram can well explain the finding that the inhomogeneity of CuIn0.25Ga0.75Se2 is higher than that of CuIn0.75Ga0.25Se2 at the same temperature, while the previous phase diagrams cannot. Hence, our phase diagram should be more reliable and applicable. [ABSTRACT FROM AUTHOR]

Atomistic simulation has been performed on La2-xSrxCuO4 to investigate its hole distribution and local structure in real space lattice. It is found that the holes introduced by Sr doping are more energetically favorable to form stripes than to be disordered. The authors verify two types of hole-stripe models (vertical and diagonal domain walls) and propose some other possible types of hole-stripe models, which are quarter or half filled. The local structure of hole stripes is found to be different from the average structure. Sr2+ ions are also found to have a thermodynamics tendency of ordering. [ABSTRACT FROM AUTHOR]

Atomistic simulation has been performed on La2-xSrxCuO4 to investigate its hole distribution and local structure in real space lattice. It is found that the holes introduced by Sr doping are more energetically favorable to form stripes than to be disordered. The authors verify two types of hole-stripe models (vertical and diagonal domain walls) and propose some other possible types of hole-stripe models, which are quarter or half filled. The local structure of hole stripes is found to be different from the average structure. Sr2+ ions are also found to have a thermodynamics tendency of ordering. [ABSTRACT FROM AUTHOR]