TY - JOUR
T1 - Density functional theory study of hypothetical PbTiO3 -based oxysulfides
AU - Brehm, John A.
AU - Takenaka, Hiroyuki
AU - Lee, Chan Woo
AU - Grinberg, Ilya
AU - Bennett, Joseph W.
AU - Schoenberg, Michael Rutenberg
AU - Rappe, Andrew M.
PY - 2014/5/14
Y1 - 2014/5/14
N2 - Using density functional theory (DFT) within the local density approximation (LDA), we calculate the physical and electronic properties of PbTiO3 (PTO) and a series of hypothetical compounds PbTiO3-xSx x=0.2, 0.25, 0.33, 0.5, 1, 2, and 3 arranged in the corner-sharing cubic perovskite structure. We determine that replacing the apical oxygen atom in the PTO tetragonal unit cell with a sulfur atom reduces the x=0 LDA calculated band gap of 1.47 eV to 0.43-0.67 eV for x=0.2-1 and increases the polarization. PBE0 and GW methods predict that the compositions x=0.2-2 will have band gaps in the visible range. For all values of x < 2, the oxysulfide perovskite retains the tetragonal phase of PbTiO3, and the a lattice parameter remains within 2.5% of the oxide. Thermodynamic analysis indicates that chemical routes using high-temperature gas, such as H2S and CS2, can be used to substitute O for S in PTO for the compositions x=0.2-0.5.
AB - Using density functional theory (DFT) within the local density approximation (LDA), we calculate the physical and electronic properties of PbTiO3 (PTO) and a series of hypothetical compounds PbTiO3-xSx x=0.2, 0.25, 0.33, 0.5, 1, 2, and 3 arranged in the corner-sharing cubic perovskite structure. We determine that replacing the apical oxygen atom in the PTO tetragonal unit cell with a sulfur atom reduces the x=0 LDA calculated band gap of 1.47 eV to 0.43-0.67 eV for x=0.2-1 and increases the polarization. PBE0 and GW methods predict that the compositions x=0.2-2 will have band gaps in the visible range. For all values of x < 2, the oxysulfide perovskite retains the tetragonal phase of PbTiO3, and the a lattice parameter remains within 2.5% of the oxide. Thermodynamic analysis indicates that chemical routes using high-temperature gas, such as H2S and CS2, can be used to substitute O for S in PTO for the compositions x=0.2-0.5.
UR - http://www.scopus.com/inward/record.url?scp=84901393203&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.89.195202
DO - 10.1103/PhysRevB.89.195202
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SN - 1098-0121
VL - 89
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 19
M1 - 195202
ER -