A Cu²⁺ ion–F Center Complex View on the Photoluminescence Quenching and Correlating Ferrimagnetism in (Cu₂⁺/Cu₁²⁺)_0.044Zn_0.956O Electrospun Nanobelts

Abstract

Unlike to the most previous reports, mixed-cation Cu(+)/Cu(2+) doping-induced novel nanoscale phenomena, including photoluminescence quenching and a correlating ferrimagnetism with Néel temperature ≈ 14 K, were found in the as-calcined (Cu2(+)/Cu1(2+))0.044Zn0.956O electrospun nanobelts (NBs). There is also high strain (up to 1.98%) and shrunk lattice distortion (ΔV/V0 ∼ 0.127%) in the (Cu2(+)/Cu1(2+))0.044Zn0.956O 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 (Cu2(+)/Cu1(2+))0.044Zn0.956O NBs. The above correlation enables the potential application of tuning of the optical and ferrimagnetic properties through strain and F-center engineering.

Bi-doping improves the magnetic properties of zinc oxide nanowires

“…14,15 Therefore, studies to determine the mechanism for the interactions of localized spins associated with native point defects have been carried out. 16 Numerous theoretical [17][18][19] and experimental 13,[20][21][22][23][24] studies related to DMS demonstrated that it is possible to achieve ferromagnetism above room temperature via the substitution of cations with transition metal (TM) ions. However, the occurrence of undesirable phase separation may cause problems with TM-doped DMS, which may deter their practical applications.…”

Robust 2D Room-Temperature Dilute Ferrimagnetism Enhancement in Freestanding Ammoniated Atom-Thin [0001] h-BN Nanoplates

“…With respect to the ultra-low-field (i.e., giant Landé factor g ∼ 20.6839), weak, and broad EPR line character of the air-calcined and N 2 -annealed 2D h-BN nanoplates, remarkably, there is only one strong symmetric EPR peak signal in NH 3 -annealed 2D h-BN nanoplates at g ∼ 2.1267 at room temperature (295 K), and g ∼ 2.5892 at 95 K, respectively. It provides clear EPR evidence for an unpaired electron trapped in the ammoniated 2D h-BN as a paramagnetic center , where bound magnetic polarons in DMSs could be activated. , The deviation of the g -factor from that of the free electron g -value ( g e ∼ 2.0023) is susceptible to the spin–orbit coupling parameter, suggesting that the electron does not freely exist (the dotted line and arrow are drawn to guide the eye); that is, there is some sort of correlation between electron and B atom site (i.e., localized charge states) in the ammoniated 2D h-BN nanoplates (see the following discussion).…”

Shape-controlled synthesis of 3D copper nicotinate hollow microstructures and their catalytic properties

“…The EPR spectrum showed similar ngerprints in the main region of the EPR spectra at g z 2. 28,29 The broad resonance signal at g ¼ 2.094 is a characteristic of Cu 2+ ion. The EPR results are in good agreement with the XRD and XPS analyses.…”