Polar P63cm phase as a marginally stable ground-state structure of InMnO3: First-principles study
1 Department of Materials Science and Engineering, and Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH) - Pohang 790-784, Republic of Korea
2 Department of Materials Science and Engineering, Massachusetts Institute of Technology (MIT) Cambridge, MA 02139, USA
Received: 3 December 2013
Accepted: 3 December 2013
To resolve a dispute associated with the ferroelectricity in hexagonal InMnO3 (h-IMO), we have examined the ground-state structure by exploiting density-functional theory calculations. It is shown that the ferroelectric phase is marginally stable over the nonpolar phase for a wide range of the external pressure. However, the computed Kohn-Sham energy predicts an interesting crossover from the polar state to the nonpolar state beginning at a compressive strain of ∼1%. The partial density of states (PDOS) supports our previous finding that the In 4d-O 2p hybridization is the main bonding mechanism directly related to the manifestation of ferroelectricity in h-IMO. In addition, the computed PDOS does not show any evidence of the In 5s-O 2p orbital overlapping which had been asserted to be the main bonding interaction in the nonpolar phase.
PACS: 77.80.-e – Ferroelectricity and antiferroelectricity / 71.15.Mb – Density functional theory, local density approximation, gradient and other corrections / 71.20.-b – Electron density of states and band structure of crystalline solids
© EPLA, 2013