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.

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.

ROOM TEMPERATURE FERROMAGNETISM IN Co-DOPED ZnO NANOPARTICLES: MILLING TIME DEPENDENCE AND ANNEALING EFFECT

2011 ◽  
Vol 10 (01n02) ◽  
pp. 307-311 ◽  
Author(s):  
BAPPADITYA PAL ◽  
P. K. GIRI
Keyword(s):  
Zno Nanoparticles ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Magnetic Impurities ◽  
Zno Nps ◽  
Small Magnitude ◽  
Doped Zno ◽  
Co Doped

We report on the occurrence of room temperature ferromagnetism in Co -doped ZnO nanoparticles (NPs). Doping is performed by ball milling of 3 wt% of Co mixed with ZnO nanopowders (commercial) for durations of 2–8 h. X-ray diffraction data and high-resolution transmission electron microscopy (HRTEM) confirm the absence of metallic Co clusters or any other phase different from würtzite-type ZnO . The magnetization (M–H curve) measured at room temperature exhibits the clear ferromagnetic characteristic with saturation magnetization (Ms) and coercive field (Hc) of the order of 3–4 emu/g and 225 Oe, respectively. Post-growth annealing at 250°C results in an increase of Ms by a small magnitude, while annealing at 500°C results in reduction of Ms. UV–visible absorption spectra show small redshift in the absorption peaks in the Co -doped ZnO NPs due to the incorporation of Co atoms in ZnO lattice. Room temperature photoluminescence studies show enhanced near-band-edge emission at 378 nm in the doped NPs as compared to the undoped NPs indicating low density of defects in the doped ZnO crystals. Contribution of intrinsic defects and magnetic impurities in the observed ferromagnetism is discussed.

scholarly journals Spectroscopic investigation of an intrinsic room temperature ferromagnetism in Co doped ZnO nanoparticles

2014 ◽  
Vol 195 ◽  
pp. 179-184 ◽  
Author(s):  
Srinatha N ◽  
Basavaraj Angadi ◽  
K.G.M. Nair ◽  
Nishad G. Deshpande ◽  
Y.C. Shao ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Spectroscopic Investigation ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
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.

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