6533b851fe1ef96bd12aa132

RESEARCH PRODUCT

Electronic structure, lattice dynamics and thermodynamic stability of paramelaconite Cu4O3

L. DebbichiM.c. Marco De LucasPeter KrügerPeter Krüger

subject

Quantitative Biology::Neurons and CognitionChemistryAb initioThermodynamicsEmpty lattice approximationElectronic structureParamelaconiteengineering.materialCondensed Matter PhysicsAb initio quantum chemistry methodsengineeringPhysical chemistryAntiferromagnetismCondensed Matter::Strongly Correlated ElectronsGeneral Materials ScienceChemical stabilityElectronic band structure

description

Abstract An ab initio study of the electronic structure, lattice dynamic and thermodynamic properties of paramelaconite Cu 4 O 3 is reported. The insulating, mixed-valence character of Cu 4 O 3 is elucidated by analyzing the band structure and the spin-orbital symmetry of the Cu-3 d hole states. Exchange coupling constants between Cu 2+ ions are computed which confirm the frustrated antiferromagnetism of the spin lattice. The lattice dynamics is studied from first principles and main features of the vibrational spectrum are assigned to the different chemical species Cu + , Cu 2+ and O. The thermodynamic stability of Cu 4 O 3 is investigated by calculating the free energy of the decomposition reaction into CuO and Cu 2 O as a function of temperature. The results agree with the available experimental data and indicate that the vibrational entropy plays an essential role for the decomposition reaction, which occurs at elevated temperatures.

yearjournalcountryeditionlanguage
2014-11-01Materials Chemistry and Physics
https://doi.org/10.1016/j.matchemphys.2014.07.046