Investigation into Structural Phase Transitions in Layered Titanium-Oxypnictides by a Computational Phonon Analysis

• Nakano, Kousuke

• Hongo, Kenta

• Maezono, Ryo

Abstract

We applied ab initio phonon analysis to layered titanium-oxypnictides, Na_2Ti_2Pn_2O (Pn = As and Sb), and found a clear contrast between the cases with lighter/heavier pnictogen in comparison with experiments. The result completely explains the experimental structure at low temperature, C2/m for Pn = As, within the conventional charge density wave, while there arise discrepancies when the pnictogen gets heavier. Our phonon calculation using the GGA-PBE functional predicts that a Cmce polymorph is more stable than the experimentally observed one (Cmcm) for Pn = Sb. On the basis of further quantitative analysis, we suggest the possibility that the GGA-PBE functional does not properly reproduce the electron correlation effects for Pn = Sb, and this could be the reason for the present discrepancy.

identifier:https://dspace.jaist.ac.jp/dspace/handle/10119/15356

Journal

• Inorganic Chemistry

  Inorganic Chemistry 56 (22), 13732-13740, 2017-11-02

  American Chemical Society

Keywords

• Layered Titanium-Oxynictides
• Phonon softening
• Superstructures

Details

• CRID: 1050564287491969024
• NII Article ID: 120006489999
• ISSN: 00201669
• ISSN: 1520510X
• DOI: 10.1021/acs.inorgchem.7b01709
• Web Site: http://hdl.handle.net/10119/15356
• Web Site: http://pubs.acs.org/doi/pdf/10.1021/acs.inorgchem.7b01709
• Web Site: https://pubs.acs.org/doi/pdf/10.1021/acs.inorgchem.7b01709
• Text Lang: en
• Article Type: journal article
• Data Source:
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  • CiNii Articles
  • KAKEN