Microstructural analysis, dielectric properties and room temperature magnetic ordering of Pr-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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Investigation on structural, optical and dielectric properties of Co doped ZnO nanoparticles synthesized by gel-combustion route

Materials Science and Engineering B ◽

10.1016/j.mseb.2012.01.022 ◽

2012 ◽

Vol 177 (5) ◽

pp. 428-435 ◽

Cited By ~ 115

Author(s):

Sajid Ali Ansari ◽

Ambreen Nisar ◽

Bushara Fatma ◽

Wasi Khan ◽

A.H. Naqvi

Keyword(s):

Dielectric Properties ◽

Zno Nanoparticles ◽

Gel Combustion ◽

Combustion Route ◽

Doped Zno ◽

Co Doped

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

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.577.19 ◽

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.

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