Over-Stoichiometry in Heavy Metal Oxides: The Case of Iono-Covalent Tantalum Trioxides

Yun Jae Lee, Taehun Lee, Aloysius Soon

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Oxides of tantalum (common examples including TaO, TaO2, and Ta2O5) are key oxide materials for modern electronic devices, such as dynamic random-access memory and field effect transistors. Of late, new forms of stable tantalum oxides have been proposed as two-dimensional nanosheet structures with a nonconventional stoichiometry of TaO3 via soft-chemical delamination of RbTaO3. However, not much is known about the elusive nanosheet-structured TaO3, unlike other closely related common trioxides of W and Mo. In this work, using first-principles density functional theory calculations, we have studied various TaO3 structures as inspired from previous theoretical and experimental studies and discuss their properties with respect to the more conventional oxide of tantalum, Ta2O5. We have calculated their thermodynamics and lattice properties and have found a new stable-layered β-TaO3 and its exfoliated monolayer phase (β′). By further analyzing their electronic structures, we discuss the mixed iono-covalent bonding characteristics in the TaO3 phases, challenging the conventional formal oxidation state model for metal oxides. Finally, we propose how these new TaO3 oxide materials may be potentially useful in photodevice applications.

Original languageEnglish
Pages (from-to)6057-6064
Number of pages8
JournalInorganic Chemistry
Volume57
Issue number10
DOIs
Publication statusPublished - 2018 May 21

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

Fingerprint Dive into the research topics of 'Over-Stoichiometry in Heavy Metal Oxides: The Case of Iono-Covalent Tantalum Trioxides'. Together they form a unique fingerprint.

  • Cite this