Defect and dopant induced room temperature ferromagnetism in Ni doped ZnO nanoparticles

Chithira, P.R.; John, Teny Theresa

doi:10.1016/j.jallcom.2018.06.336

Cited by 51 publications

(11 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The analysis is done at room temperature with an excitation source of 532 nm in the range of 200 to 1000 cm –1 . The detailed Raman analysis of the undoped sample is given elsewhere . The phonon frequency at around 440 cm –1 represents the E 2 high mode, which involves the motion of oxygen atoms in the wurtzite lattice and is a typical Raman peak of ZnO .…”

Section: Results and Discussionmentioning

confidence: 99%

“…Figure a–d shows the room temperature M - H data of Fe-doped ZnO samples. The undoped ZnO sample is diamagnetic; the details are given in our previous reported work . Fe1 shows RTFM with a coercivity of ∼70 Oe.…”

Section: Results and Discussionmentioning

confidence: 99%

“…The detailed Raman analysis of the undoped sample is given elsewhere. 21 The phonon frequency at around 440 cm −1 represents the E 2 high mode, which involves the motion of oxygen atoms in the wurtzite lattice and is a typical Raman peak of ZnO. 22 The mode at around 407 cm −1 present in the sample is characterized as the E 1 (TO) optical phonon mode.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…The undoped ZnO sample is diamagnetic; the details are given in our previous reported work. 21 Fe1 shows RTFM with a coercivity of ∼70 Oe. The non-saturating, linear magnetic moment at the higher applied magnetic field is due to the paramagnetic contribution from the uncoupled Fe 3+ ions.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

See 3 more Smart Citations

Local Structural Studies Through EXAFS and Effect of Fe²⁺or Fe³⁺ Existence in ZnO Nanoparticles

et al. 2021

Self Cite

View full text Add to dashboard Cite

A simple solution-based chemical precipitation method was used to synthesize the Fe-doped ZnO nanoparticles. X-ray Photoelectron Spectroscopy (XPS) measurement showed that mostly Fe2+ ions are incorporated in a lower percentage of Fe doping, while a higher percentage leads to Fe3+. The broad absorption band in the visible range shows the d–d crystal field transitions between the multiplets of 3d5 configuration of the high spin Fe3+ substituting Zn2+ under the influence of a tetrahedral ZnO crystal field. Raman measurement also supports the optical absorption data. ESR results show that the occurrence of broad signals is due to the exchange interactions among the TM ions in the doped samples. Fe exists in a mixed phase in Fe1 and the wide curve in Fe10 is due to the exchange interaction among Fe3+– Fe3+. EXAFS measurements confirm that the spectral features showing the peak edge position is similar to Fe2O3 corresponding to the Fe3+ state. From this, it can be inferred that Fe exists mostly in a +3 oxidation state in all the samples, but there may be existence of +2 states in the surface layers as observed from XPS measurement. Fe1 shows RTFM with a coercivity of ∼70 Oe. The non-saturating, linear magnetic moment at higher applied magnetic field is due to the paramagnetic contribution from the uncoupled Fe3+ ions.

show abstract

Section: Results and Discussionmentioning

confidence: 99%

Section: Results and Discussionmentioning

confidence: 99%

Section: ■ Results and Discussionmentioning

confidence: 99%

Section: ■ Results and Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Local Structural Studies Through EXAFS and Effect of Fe²⁺or Fe³⁺ Existence in ZnO Nanoparticles

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…The UV excitation band at 280 nm originates from the Ga-O charge transfer transition of the ZGGO host, and the other excitation bands can be attributed to the characteristic peaks of Ni 2+ ions. [23][24][25] Upon 625 nm excitation, a broad emission peak at 1290 nm can be detected, which corresponds to the characteristic emission of Ni 2+ ions. 26,27 It is found that, with increasing Ni 2+ concentration, the 1290 nm emission intensity shows an initial rising and then decreasing trend.…”

Section: Resultsmentioning

confidence: 99%

Doping and luminescence mechanisms of broadband NIR‐II emitting Zn₂₍₁₋_x₎Ni₂_xGa₃Ge_0.75O₈ nanoparticles

et al. 2022

View full text Add to dashboard Cite

In this study, Zn 2(1−x) Ni 2x Ga 3 Ge 0.75 O 8 (x = 0.0002, 0.001, 0.002, 0.010, 0.020, and 0.030) nanoparticles with broadband NIR-II emissions were synthesized by a hydrothermal synthesis combined with a vacuum annealing. For the Ni 2+doped ZGGO samples (x = 0-0.03), with increasing concentration, the particle shape gradually becomes spherical and the average particle size decreases from 124.4 to 74.2 nm. Meanwhile, for the ZGGO:Ni 2+ 0.01 nanoparticles, the asymmetrically broad emission peak around 1290 nm, which is the superposition of the two peaks locating at 1280 and 1450 nm, can be observed and the afterglow time exceeds 30 min. Based on the spectral data, luminescence decay curves, first-principles calculations, and Tanabe-Sugano theory, it is found that Ni 2+ ions can occupy not only tetrahedral but also octahedral Zn 2+ sites (locating in anti-site defects pair) in the spinel ZGGO host, and they have the contributions to the 1450 and 1280 nm emission peaks, respectively. Furthermore, the surface-modified ZGGO:Ni 2+ nanoparticles exhibited good stability in the H 2 O and HSA (5% human serum albumin, pH = 7.4) solutions and the occurred agglomeration sinking in the SLS (simulate lysosomal solution, pH = 4.7) solution. Compared to the narrow-band NIR-II emitting persistent luminescence nanoparticles (ZGGO:Cr 3+ ,Er 3+ and ZGGO:Cr 3+ ,Nd 3+ ), broadband NIR-II emitting persistent luminescence nanoparticles (ZGGO:Ni 2+ NIR-II) possess stronger persistent luminescence intensity and can effectively avoid the water absorption of biological tissues. Our results suggest that ZGGO:Ni 2+ persistent luminescence nanoparticles have a potential to become optical probes for deep-tissue autofluorescence-free bioimaging in the biomedical field.

show abstract

Effect of oxygen vacancy defect regeneration on photocatalytic properties of ZnO nanorods

Liu

et al. 2020

Appl. Phys. A

View full text Add to dashboard Cite

Defect and dopant induced room temperature ferromagnetism in Ni doped ZnO nanoparticles

Cited by 51 publications

References 61 publications

Local Structural Studies Through EXAFS and Effect of Fe²⁺or Fe³⁺ Existence in ZnO Nanoparticles

Local Structural Studies Through EXAFS and Effect of Fe²⁺or Fe³⁺ Existence in ZnO Nanoparticles

Doping and luminescence mechanisms of broadband NIR‐II emitting Zn₂₍₁₋_x₎Ni₂_xGa₃Ge_0.75O₈ nanoparticles

Effect of oxygen vacancy defect regeneration on photocatalytic properties of ZnO nanorods

Contact Info

Product

Resources

About

Defect and dopant induced room temperature ferromagnetism in Ni doped ZnO nanoparticles

Cited by 51 publications

References 61 publications

Local Structural Studies Through EXAFS and Effect of Fe2+or Fe3+ Existence in ZnO Nanoparticles

Local Structural Studies Through EXAFS and Effect of Fe2+or Fe3+ Existence in ZnO Nanoparticles

Doping and luminescence mechanisms of broadband NIR‐II emitting Zn2(1−x)Ni2xGa3Ge0.75O8 nanoparticles

Effect of oxygen vacancy defect regeneration on photocatalytic properties of ZnO nanorods

Contact Info

Product

Resources

About

Local Structural Studies Through EXAFS and Effect of Fe²⁺or Fe³⁺ Existence in ZnO Nanoparticles

Local Structural Studies Through EXAFS and Effect of Fe²⁺or Fe³⁺ Existence in ZnO Nanoparticles

Doping and luminescence mechanisms of broadband NIR‐II emitting Zn₂₍₁₋_x₎Ni₂_xGa₃Ge_0.75O₈ nanoparticles