Revealing the Role of Hydrogen in Electron-Doping Mottronics for Strongly Correlated Vanadium Dioxide

• DOI: 10.1021/acs.jpclett.2c02001
• Publication Date: 2022-08-23T12:46:44Z
• Authors: Xuanchi Zhou; Haifan Li; Fanqi Meng; Wei Mao; Jiaou Wang; Yong Jiang; Katsuyuki Fukutani; Markus Wilde; Bunshi Fugetsu; Ichiro Sakata; Nuofu Chen; Jikun Chen
• Keywords: Vanadium dioxide

Hydrogen-associated electron-doping Mottronics for d-band correlated oxides (e.g., VO2) opens up a new paradigm to regulate the electronic functionality via directly manipulating orbital configuration and occupancy. Nevertheless, role of hydrogen in Mottronic transition VO2 is yet unclear because opposite reconfigurations toward either metallic or highly insulating states were both reported. Herein, we demonstrate root cause such hydrogen-induced multiple phase transitions by 1H quantification using nuclear reaction analysis. A low hydrogenation temperature demonstrated be vital achieving large concentration (nH ≈ 1022 cm–3) that further enhances t2g occupancy trigger electron localizations. In contrast, elevating temperatures surprisingly reduces nH ∼1021 cm–3 but forms more stable H0.06VO2. This leads recognition weaker interaction triggers localization within Mottronically enhancing occupancies.