Carrier and vacancy mediated ferrimagnetism in Cu doped rutile TiO2. Issue 8 (3rd February 2021)

• Record Type: Journal Article
• Authors: Lin, Qiaolu; Xu, Nannan; Li, Gongping; Qian, Zhengfang; Liu, Huan; Wang, Renheng
• Is Part Of: Journal of materials chemistry. Volume 9:Issue 8(2021)
• Page Start: 2858
• Page End: 2863
• Publication Date: 2021-02-03
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0tc05654e
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : The magnetic properties of Cu doped rutile TiO2 modulated by valency, concentration and distribution of substituted impurity atoms, and subjected to O vacancy and charge carriers. Abstract : Cu doped TiO2 can help to understand the magnetic origin of TiO2 -based diluted magnetic semiconductors. As such, herein, we calculated the systems of TiO2 with different valence states and concentrations of Cu substituted for Zn as well as Cu substitution and vacancy complex defects. For the substitution ratio of 1/48, ferromagnetism appears only in Cu 0 substitution system. By increasing the concentration of Cu to 1/24, Cu 2+ substitution system also shows a ferromagnetic ground state when the Cu substitutions are not separated by empty regions (low charge density regions) and along the (111) direction. The Cu substitution and oxygen vacancy complex defect systems are easily polarized due to carriers induced by vacancy. Carriers change the bond of Ti ions around the defect, and arouse residual magnetic moment; however, the contribution of carriers to the electronic structure had a saturation limit. Oxygen vacancy leads to the formation of non-ferromagnetic coupling between two Cu substitutions in a 2 × 2 × 2 supercell. Cu substitution and Ti vacancy composite defect give rise to the weakening of p–d hybridization, and the lattice distortion caused by defects and the strong interaction of Cu–O bond is the source of ferromagnetism. The room-temperature ferromagnetism in Cu doped monocrystalline TiO2 samples could be mediated by vacancies or carriers.