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

2019 ◽  
Vol 91 (2) ◽  
pp. 324-334 ◽  
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

Photoluminescence and Magnetic Properties of Undoped and (Mn, Co) co-doped ZnO Nanoparticles

2020 ◽  
Vol 16 (4) ◽  
pp. 655-666
Author(s):  
Mona Rekaby
Keyword(s):  
Magnetic Properties ◽  
Zno Nanoparticles ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Structural Defects ◽  
Ferromagnetic Behavior ◽  
Secondary Phases ◽  
Antiferromagnetic Ordering ◽  
Doped Zno ◽  
Co Doped

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.

Structural and Magnetic Properties of Mn/Fe co-Doped ZnO Thin Films Prepared by Sol–Gel Technique

2014 ◽  
Vol 50 (8) ◽  
pp. 1-4 ◽  
Author(s):  
Robina Ashraf ◽  
Saira Riaz ◽  
Mahwish Bashir ◽  
Usman Khan ◽  
Shahzad Naseem
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Sol Gel ◽  
Zno Thin Films ◽  
Gel Technique ◽  
Structural And Magnetic Properties ◽  
Doped Zno ◽  
Co Doped

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

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.

Effect of cobalt doping on microstructures and dielectric properties of ZnO

2019 ◽  
Vol 97 (3) ◽  
pp. 227-232 ◽  
Author(s):  
Ye Zhao ◽  
Fan Tong ◽  
Mao Hua Wang
Keyword(s):  
Zno Nanoparticles ◽  
Sol Gel ◽  
Hexagonal Wurtzite Structure ◽  
Sem Analysis ◽  
Co Doping ◽  
In Doping ◽  
Zno Powders ◽  
Doped Zno ◽  
Zno Crystal ◽  
Co Doped

Pure and cobalt-doped ZnO nanoparticles (2.5, 5, 7.5, and 10 atom % Co) are synthesized by sol–gel method. The as-synthesized nanoparticles are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FE-SEM) analysis. The nanoparticles of 0, 2.5, and 5 atom % Co-doped ZnO exhibited hexagonal wurtzite structure and have no other phases. Moreover, the (101) diffraction peaks position of Co-doped ZnO shift toward a smaller value of diffraction angle compared with pure ZnO powders. The results confirm that Co ions were well incorporated into ZnO crystal lattice. Simultaneously, Co doping also inhibited the growth of particles, and the crystallite size decreased from 43.11 nm to 36.63 nm with the increase in doping concentration from 0 to 10 atom %. The values of the optical band gap of all Co-doped ZnO nanoparticles gradually decreased from 3.09 eV to 2.66 eV with increasing Co content. Particular, the dielectric constant of all Co-doped ZnO ceramics gradually increased from 1.62 × 103 to 20.52 × 103, and the dielectric loss decreased from 2.36 to 1.28 when Co content increased from 0 to 10 atom %.

scholarly journals Synthesis of Cu and Ce co-doped ZnO nanoparticles: crystallographic, optical, molecular, morphological and magnetic studies

2017 ◽  
Vol 35 (2) ◽  
pp. 427-434 ◽  
Author(s):  
Mohit Rawat ◽  
Jasmeet Singh ◽  
Jagpreet Singh ◽  
Chamkaur Singh ◽  
Amritpal Singh ◽  
...  
Keyword(s):  
Room Temperature ◽  
Sol Gel ◽  
Research Work ◽  
Yellow Emission ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Ferromagnetic Behavior ◽  
Magnetic Studies ◽  
Transmission Electron Microscopy Analysis ◽  
Co Doped

Abstract In the present research work, crystallographic, optical, molecular, morphological and magnetic properties of Zn1-xCuxO (ZnCu) and Zn1-x-yCeyCuxO (ZnCeCu) nanoparticles have been investigated. Polyvinyl alcohol (PVA) coated ZnCu and ZnCeCu nanoparticles have been synthesized by chemical sol-gel method and thoroughly studied using various characterization techniques. X-ray diffraction pattern indicates the wurtzite structure of the synthesized ZnCu and ZnCeCu particles. Transmission electron microscopy analysis shows that the synthesized ZnCu and ZnCeCu particles are of spherical shape, having average sizes of 27 nm and 23 nm, respectively. The incorporation of Cu and Ce in the ZnO lattice has been confirmed through Fourier transform infrared spectroscopy. Room temperature photoluminescence spectra of the ZnO doped with Cu and co-doped Ce display two emission bands, predominant ultra-violet near-band edge emission at 409.9 nm (3 eV) and a weak green-yellow emission at 432.65 nm (2.27 eV). Room temperature magnetic study confirms the diamagnetic behavior of ZnCu and ferromagnetic behavior of ZnCeCu.

The Room Temperature Ferromagnetism of (N, Co) Co-Doped ZnO Nanopaticles

2014 ◽  
Vol 577 ◽  
pp. 19-22
Author(s):  
Ping Cao ◽  
Yue Bai ◽  
Zhi Qu
Keyword(s):  
Zno Nanoparticles ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Crystal Lattices ◽  
Grown Sample ◽  
N Doping ◽  
Doped Zno ◽  
Zno Crystal ◽  
Zno Nanopaticles ◽  
Co Doped

Co-doped ZnO nanoparticles were fabricated by an electrodeposition method. The XPS results show Co ions have doped into the ZnO crystal lattices successfully. The as-grown sample has no ferromagnetism at room temperature. But after an ammine plasma treatment the room temperature ferromagnetism were detected on Co0.04Zn0.96O nanoparticles. The Hall measurement reveals after the treatment the resistivity increase by three orders of magnitude. Although the aspect conductivity is n type, some holes generated by N doping play an important role to induce the ferromagnetic properties for Co doped ZnO sample.

Sol-gel derived Al and Ga co-doped ZnO nanoparticles: Structural, morphological and optical investigation

Optik ◽  
2019 ◽  
Vol 192 ◽  
pp. 162942 ◽  
Author(s):  
Long Huang ◽  
Yihua Sun ◽  
Mingbo Li ◽  
Yasha Yi ◽  
Lihua Jiang ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Sol Gel ◽  
Optical Investigation ◽  
Doped Zno ◽  
Co Doped

scholarly journals Doping effect and oxygen defects boost room temperature ferromagnetism of Co-doped ZnO nanoparticles: experimental and theoretical studies

RSC Advances ◽  
2019 ◽  
Vol 9 (40) ◽  
pp. 23012-23020 ◽  
Author(s):  
Yan Zong ◽  
Yong Sun ◽  
Shiyan Meng ◽  
Yajing Wang ◽  
Hongna Xing ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Decomposition Method ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Theoretical Studies ◽  
Thermal Decomposition Method ◽  
Oxygen Defects ◽  
Doped Zno ◽  
Experimental And Theoretical Studies ◽  
Co Doped

Co-doped ZnO nanoparticles with different dosage concentrations were fabricated by a thermal decomposition method.

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