2 research outputs found
Anharmonicity and structural phase transition in the Mott insulator CuPO
Ab initio investigations of structural, electronic, and dynamical properties
of the high-temperature phase of copper pyrophosphate were performed
using density functional theory. The electronic band structure shows the Mott
insulating state due to electron correlations in copper ions. By calculating
phonon dispersion relations, the soft mode at the A point of the Brillouin zone
was revealed, showing the dynamical instability of the phase at low
temperatures. The double-well potential connected with the soft mode is derived
and the mechanism of the structural phase transition to the phase is
discussed. The self-consistent phonon calculations based on the
temperature-dependent effective potential show the stabilization of the
phase at high temperatures, due to the anharmonic effects. The pronounced
temperature dependence and the large line width of the soft mode indicate an
essential role of anharmonicity in the structural phase transition
Anharmonicity and structural phase transition in the Mott insulator Cu2P2O7
Ab initio investigations of the structural, electronic, and dynamical properties of the high-temperature 0 phase of copper pyrophosphate were performed using density functional theory. The electronic band structure shows the Mott insulating state due to electron correlations in the copper ions. By calculating phonon dispersion relations, the soft mode at the A point of the Brillouin zone was revealed, showing the dynamical instability of the 0 phase at low temperatures. The double-well potential connected with the soft mode is derived and the mechanism of the structural phase transition to the & alpha; phase is discussed. The self-consistent phonon calculations based on the temperature-dependent effective potential show the stabilization of the 0 phase at high temperatures, due to the anharmonic effects. The pronounced temperature dependence and the large linewidth of the soft mode indicate an essential role of anharmonicity in the structural phase transition.Web of Science10810art. no. 10410