Electronic structure and stability of low symmetry Ta2O5polymorphs. Issue 6 (20th May 2014)

• Record Type: Journal Article
• Authors: Kim, Ja‐Yong; Magyari‐Köpe, Blanka; Lee, Kee‐Jeung; Kim, Hyeong‐Soo; Lee, Seok‐Hee; Nishi, Yoshio
• Is Part Of: Physica status solidi. Volume 8:Issue 6(2014:Jun.)
• Page Start: 560
• Page End: 565
• Publication Date: 2014-05-20
• Subjects: Solid state physics -- Periodicals; 530.4105
• DOI: 10.1002/pssr.201409018
• Languages: English
• ISSNs: 1862-6254

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p> <boxed-text content-type="graphic" position="anchor" orientation="portrait"> <graphic position="anchor" mimetype="image" xlink:href="ark:/27927/pghmhqk7d3" orientation="portrait" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /> </boxed-text> </p> <p>The structures and electronic properties of Ta₂O₅ polymorphs were calculated using density‐functional theory employing the generalized gradient approximation with on‐site Coulomb corrections. Using this approach, a pseudo‐hexagonal structure was found to be a stable polymorph of Ta₂O₅ over δ‐ and β‐Ta₂O₅ and metastable relative to other recently proposed structures. Its diffraction spectrum and bandgap energy are in good agreement with experimental data. Therefore, the pseudo‐hexagonal structure might form in polycrystalline films and affect the switching process of resistive memory devices. Moreover, a neutral oxygen vacancy is found to induce an occupied defect state at 2.5 eV above the top of the valence band, in agreement with X‐ray photoelectron spectroscopy results. (© 2014 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)</p> </abstract>