VZn–H complex defect induced ferromagnetic behavior of unintentional hydrogen doped ZnO nanoparticles

Objective: The influence of Manganese (Mn2+) and Cobalt (Co2+) ions doping on the optical and magnetic properties of ZnO nanoparticles was studied. Methods: Nanoparticle samples of type ZnO, Zn0.97Mn0.03O, Zn0.96Mn0.03Co0.01O, Zn0.95Mn0.03 Co0.02O, Zn0.93Mn0.03Co0.04O, and Zn0.91Mn0.03Co0.06O were synthesized using the wet chemical coprecipitation method. Results: X-ray powder diffraction (XRD) patterns revealed that the prepared samples exhibited a single phase of hexagonal wurtzite structure without any existence of secondary phases. Transmission electron microscope (TEM) images clarified that Co doping at high concentrations has the ability to alter the morphologies of the samples from spherical shaped nanoparticles (NPS) to nanorods (NRs) shaped particles. The different vibrational modes of the prepared samples were analyzed through Fourier transform infrared (FTIR) measurements. The optical characteristics and structural defects of the samples were studied through Photoluminescence (PL) spectroscopy. PL results clarified that Mn2+ and Co2+ doping quenched the recombination of electron-hole pairs and enhanced the number of point defects relative to the undoped ZnO sample. Magnetic measurements were carried out at room temperature using a vibrating sample magnetometer (VSM). (Mn, Co) co-doped ZnO samples exhibited a ferromagnetic behavior coupled with paramagnetic and weak diamagnetic contributions. Conclusion: Mn2+ and Co2+ doping enhanced the room temperature Ferromagnetic (RTFM) behavior of ZnO. In addition, the signature for antiferromagnetic ordering between the Co ions was revealed. Moreover, a strong correlation between the magnetic and optical behavior of the (Mn, Co) co-doped ZnO was analyzed.

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Assessment of Magnetic Properties between Fe and Ni Doped ZnO Nanoparticles Synthesized by Microwave Assisted Synthesis Method

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.317.119 ◽

2021 ◽

Vol 317 ◽

pp. 119-124

Author(s):

Sabiu Said Abdullahi ◽

Garba Shehu Musa Galadanci ◽

Norlaily Mohd Saiden ◽

Josephine Ying Chyi Liew

Keyword(s):

Magnetic Properties ◽

Zno Nanoparticles ◽

Room Temperature ◽

Synthesis Method ◽

Dilute Magnetic Semiconductors ◽

High Coercivity ◽

Microwave Assisted Synthesis ◽

Ferromagnetic Behavior ◽

Microwave Assisted ◽

Doped Zno

The emergence of Dilute Magnetic Semiconductors (DMS) with a potentials for spintronic application have attracted much researches attention, special consideration has been given to ZnO semiconductor material due to its wide band gap of 3.37 eV, large exciting binding energy of 60 meV, moreover, its ferromagnetic behavior at room temperature when doped with transition metals. MxZn1-xO (M = Fe or Ni) nanoparticles were synthesized by microwave assisted synthesis method calcined at 600°C. The structural, morphological and magnetic properties of these nanoparticles were studied using X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Vibrating Sample Magnetometer (VSM) respectively. Single phase Wurtzite hexagonal crystal structure was observed for the undoped and Fe doped ZnO nanoparticles with no any impurity, whereas Ni doped ZnO nanoparticles shows the formation of NiO impurities. The magnetic measurement reveals a diamagnetic behavior for the undoped ZnO meanwhile a clear room temperature ferromagnetism was observed for both Fe and Ni doped ZnO. Fe doped ZnO present a high saturation magnetization compared to Ni doped ZnO. However, Ni doped ZnO present high coercivity. The research was confirmed that Fe doped ZnO material will be good material combination for spintronic applications.

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Enhancement of room temperature ferromagnetic behavior of Co-doped ZnO nanoparticles synthesized via sol–gel technique

Journal of Sol-Gel Science and Technology ◽

10.1007/s10971-019-05004-4 ◽

2019 ◽

Vol 91 (2) ◽

pp. 324-334 ◽

Cited By ~ 2

Author(s):

Niraj K. Singh ◽

Vaibhav Koutu ◽

M. M. Malik

Keyword(s):

Zno Nanoparticles ◽

Room Temperature ◽

Sol Gel ◽

Ferromagnetic Behavior ◽

Gel Technique ◽

Doped Zno ◽

Co Doped

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Structural, Optical and Room Temperature Magnetic Study of Mn-Doped ZnO Nanoparticles

NANO ◽

10.1142/s1793292016500429 ◽

2016 ◽

Vol 11 (04) ◽

pp. 1650042 ◽

Cited By ~ 10

Author(s):

Majed Sharrouf ◽

Ramadan Awad ◽

Salem Marhaba ◽

Douaa El-Said Bakeer

Keyword(s):

Zno Nanoparticles ◽

Room Temperature ◽

Xrd Analysis ◽

Peak Shift ◽

Antiferromagnetic Coupling ◽

Ferromagnetic Behavior ◽

Two Samples ◽

Doped Zno ◽

Co Precipitation ◽

Mn Doped

Undoped and Mn-doped ZnO nanoparticles (Zn[Formula: see text]MnxO), with nominal weight percentages [Formula: see text], have been synthesized by co-precipitation technique. The synthesized nanoparticles are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV) and Fourier transform infrared spectroscopy (FTIR). From XRD analysis, the compound ZnMnO3 is formed for [Formula: see text] with cubic structure ([Formula: see text][Formula: see text]Å) and its concentration increases with x. Moreover, XRD analysis reveals the wurtzite hexagonal crystal structure for ZnO. The lattice parameters (a and c) of Zn[Formula: see text]MnxO are calculated and they increase with the doping concentration of Mn as a consequence of the larger ionic size of Mn[Formula: see text] ions compared to Zn[Formula: see text] ions. The crystallite size is calculated for all the samples using Debye–Scherrer’s method (SSM), Williamson–Hall methods (UDM, USDM and UDEDM) and Size-Strain Plot method (SSP), and the results are in good agreement with TEM. The presence of functional groups and the chemical bonding is confirmed by FTIR spectra that shows a peak shift between undoped and doped ZnO. The energy bandgap [Formula: see text] is calculated for different concentrations of Mn [Formula: see text] by using the UV-visible optical spectroscopy, between 300[Formula: see text]nm and 800[Formula: see text]nm, showing a noticeable drop in [Formula: see text] with x. At room temperature, the magnetization of the samples reveals the intrinsic ferromagnetic (FM) behavior of undoped ZnO, ferromagnetic behavior of ZnxMn[Formula: see text]O [Formula: see text] and the co-existence of ferromagnetic and paramagnetic behavior for ZnxMn[Formula: see text]O [Formula: see text]. This ferromagnetism is decreased for the doped samples as a consequence of antiferromagnetic coupling between Mn ions. The two samples correspond to [Formula: see text] and [Formula: see text], tend to be superparamagnetic because of the formation of single domain particles as a consequence of small particle size. [Formula: see text] shows an optimum value of Mn concentration for maximum saturation magnetization and the best ferromagnetic nature.

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Structural, Morphological, Optical, and Room Temperature Magnetic Characterization on Pure and Sm-Doped ZnO Nanoparticles

Journal of Nanomaterials ◽

10.1155/2018/7096195 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 11

Author(s):

Khalil Badreddine ◽

I. Kazah ◽

M. Rekaby ◽

R. Awad

Keyword(s):

Crystallite Size ◽

Zno Nanoparticles ◽

Room Temperature ◽

Magnetic Hysteresis ◽

Hexagonal Wurtzite Structure ◽

Xrd Analysis ◽

Peak Shift ◽

Band Gap Energy ◽

Ferromagnetic Behavior ◽

Doped Zno

Nano crystalline Zn1-xSmxO, (0.00 ≤ x ≤ 0.10), were prepared by wet chemical coprecipitation method. The effect of samarium doping on the structural, morphological, optical, and magnetic properties of ZnO nanoparticles was examined by X-ray powder diffraction (XRD), Transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), Ultraviolet-visible spectroscopy (UV) and M-H magnetic hysteresis. XRD analysis showed the hexagonal wurtzite structure of ZnO. The absence of Sm2O3 as separate phase may be attributed to the complete dissolving of samarium in ZnO lattice. The lattice parameters (a and c) of Zn1-xSmxO were calculated and they fluctuated with the increase of Sm doping which indicated that the structure of ZnO was perturbed by the doping of Sm. The crystallite size was computed for all the samples using Debye-Scherrer’s method. The crystallite size decreased with the increase of Sm doping. TEM micrographs revealed that the size and the shape of the ZnO nanocomposites were changed by modifying the doping level of samarium. FTIR analysis spectrum confirmed the formation of ZnO phase and revealed a peak shift between pure and Sm-doped ZnO. The band gap energy and Urbach energy were calculated for Zn1-xSmxO, (0.00 ≤ x ≤ 0.10). The band energy gaps of pure and Sm doped ZnO samples are in the range 2.6–2.98 eV. M-H hysteresis inspection, at room temperature, showed that the pure ZnO exhibited a ferromagnetic behavior incorporated with diamagnetic and paramagnetic contributions. Ferromagnetic behavior was reduced for the doped samples with x=0.01 and x=0.04. The samples with x=0.02 and 0.06 ≤ x ≤ 0.10 tend to be superparamagnetic. The saturation magnetization (Ms), the coercivity (Hc), and the retentivity (Mr) were recorded for Zn1-xSmxO, (0.00 ≤ x ≤ 0.10).

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Comparative Study of Pure Zno and Copper Doped Zno Nanoparticles Synthesised via Co-Precipitation Method

ScieXplore International Journal of Research in Science ◽

10.15613/sijrs/2014/v1i2/67542 ◽

2014 ◽

Vol 1 (2) ◽

pp. 73 ◽

Cited By ~ 1

Author(s):

V. Kalaiselvi ◽

N. Jayamani ◽

M. Revathi

Keyword(s):

Comparative Study ◽

Zno Nanoparticles ◽

Precipitation Method ◽

Doped Zno ◽

Co Precipitation

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The Crystalline Structure, Optical and Conductivity Properties of Fluorine Doped ZnO Nanoparticles

Journal of Nano- and Electronic Physics ◽

10.21272/jnep.11(3).03002 ◽

2019 ◽

Vol 11 (3) ◽

pp. 03002-1-03002-5 ◽

Cited By ~ 2

Author(s):

A. Diha ◽

◽

S. Benramache ◽

L. Fellah ◽

◽

...

Keyword(s):

Crystalline Structure ◽

Zno Nanoparticles ◽

Doped Zno

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Role of Sm3+ Doping on Structural, Optical and Photoluminescence Properties of ZnO Nanoparticles Synthesized by Sol-gel Auto- combustion Method

Current Nanomaterials ◽

10.2174/2405461505999200930141732 ◽

2020 ◽

Vol 5 (3) ◽

pp. 236-251

Author(s):

Eshwara I. Naik ◽

Halehatty S.B. Naik ◽

Ranganaik Viswanath

Keyword(s):

Zno Nanoparticles ◽

Sol Gel ◽

Combustion Method ◽

Content Increase ◽

Photoluminescence Properties ◽

Tem Analysis ◽

Auto Combustion ◽

Ion Doping ◽

Doped Zno ◽

Pl Intensity

Background: Various interesting consequences are reported on structural, optical, and photoluminescence properties of Zn1-xSmxO (x=0, 0.01, 0.03 and 0.05) nanoparticles synthesized by sol-gel auto-combustion route. Objective: This study aimed to examine the effects of Sm3+-doping on structural and photoluminescence properties of ZnO nanoparticles. Methods: Zn1-xSmxO (x=0, 0.01, 0.03 and 0.05) nanoparticles were synthesized by sol-gel auto combustion method. Results: XRD patterns confirmed the Sm3+ ion substitution through the undisturbed wurtzite structure of ZnO. The crystallite size was decreased from 24.33 to 18.46 nm with Sm3+ doping. The hexagonal and spherical morphology of nanoparticles was confirmed by TEM analysis. UV-visible studies showed that Sm3+ ion doping improved the visible light absorption capacity of Sm3+ iondoped ZnO nanoparticles. PL spectra of Sm3+ ion-doped ZnO nanoparticles showed an orange-red emission peak corresponding to 4G5/2→6HJ (J=7/2, 9/2 and 11/2) transition of Sm3+ ion. Sm3+ ion-induced PL was proposed with a substantial increase in PL intensity with a blue shift in peak upon Sm3+ content increase. Conclusion: Absorption peaks associated with doped ZnO nanoparticles were moved to a longer wavelength side compared to ZnO, with bandgap declines when Sm3+ ions concentration was increased. PL studies concluded that ZnO emission properties could be tuned in the red region along with the existence of blue peaks upon Sm3+ ion doping, which also results in enhancing the PL intensity. These latest properties related to Sm3+ ion-doped nanoparticles prepared by a cost-efficient process appear to be interesting in the field of optoelectronic applications, which makes them a prominent candidate in the form of red light-emitting diodes.

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