A Cu~(2+) ion-F Center Complex View on the Photoluminescence Quenching and Correlating Ferrimagnetism in (Cu~(2+)/ Cu_1~(2+))_(0.044)Zn_(0.956)O Electrospun Nanobelts

摘要

Unlike to the most previous reports, mixed-cation Cu~+/Cu~(2+) doping-induced novel nanoscale phenomena, including photoluminescence quenching and a correlating ferrimagnetism with Neel temperature ≈ 14 K, were found in the as-calcined (Cu~(2+)/ Cu_1~(2+))_(0.044)Zn_(0.956)O electrospun nanobelts (NBs). There is also high strain (up to 1.98%) and shrunk lattice distortion (ΔV/V0 ～ 0.127%) in the (Cu_2~+/Cu_1~(2+))_(0.044)Zn_(0.956)O NBs, leading to broken lattice symmetry in conjunction with nonstoichiometry (i.e., oxygen vacancies or accurate F centers), which could be possible origins of ferrimagnetism in the Cu-doped ZnO NBs. Electron paramagnetic resonance spectra reveal that there are giant and anisotropic g factors, suggesting that there is strong anisotropic spin-orbit interaction between the Cu~(2+) ion and F center (i.e., forming Cu~(2+)—F~+ complexes) in the (Cu~(2+)/Cu_1~(2+))_(0.044)Zn_(0.956)O NBs. The above correlation enables the potential application of tuning of the optical and ferrimagnetic properties through strain and F- center engineering.