Eur. Phys. J. B (2016) 89: 265
https://doi.org/10.1140/epjb/e2016-70381-2

Regular Article

The impact of the dopants on the formation of conductive path in titanium dioxide: ab initio calculations

¹ Institute of Intelligent Structure and System, Soochow University, Suzhou 215006, P.R. China
² Institute of Intelligent Structure and System, School of Electronics & Information Engineering, Soochow University, Suzhou 215006, P.R. China

^a e-mail: mail_lingfeng@aliyun.com

Received: 15 June 2016
Received in final form: 26 September 2016
Published online: 5 December 2016

Abstract

Ab initio calculations are performed about the dependent characteristics of the conductive path on Ti/Cu/Zr interstitials and oxygen vacancies in rutile-type titanium dioxide. It is found that eight oxygen vacancies in two columns around five Ti-ions could lead to a conductive path. Besides, the conductive path will occur when additional four oxygen vacancies exist at the third column in ⟨ 110 ⟩ direction rather than on (110) facet. Oxygen vacancies at the third and fourth columns on (110) facet are considered and lead to a conductive path. Furthermore, one or three metal interstitials, such as Ti, Cu or Zr, are doped in titanium dioxide with three columns of oxygen vacancies on (110) facet, respectively. The conductive path is only found in the structure above with three Ti interstitials. We conclude that more Ti interstitials doping in reduced TiO₂ benefit the formation of stable conductive path in resistive random access memory.