First-principles study on defected titanium dioxide with the Zr substitution for improved reliability of the conduction pathLei Li, Wenshi Li, Aimin Ji, Ziou Wang, Canyan Zhu, Lijun Zhang, Jianfeng Yang and Ling-Feng MaoEur. Phys. J. Appl. Phys., 70 1 (2015) 10103DOI: https://doi.org/10.1051/epjap/2015150010