Zinc Vacancy-Induced Room-Temperature Ferromagnetism in Undoped ZnO Thin Films
Figure 4
(a–c) Normalized XPS O 1s scans of ZnO samples: as-grown, annealed at 500°C in H2 atmosphere, and annealed at 500°C in O2 atmosphere; (d) The ratio of HBEC/LBEC peak and magnetization of as-grown, annealed (500°C + H2), and annealed (500°C + O2) ZnO samples; (e-f) Corresponding ratios of HBEC/LBEC peak and magnetizations of samples annealed at different temperatures in H2 and O2 atmosphere, respectively.