Magnetic behavior of nanocrystalline powders of Co-doped ZnO diluted magnetic semiconductors synthesized by polymerizable precursor method

Maensiri, Santi; Sreesongmuang, Jakkapon; Thomas, Chunpen; Klinkaewnarong, Jutharatana

doi:10.1016/j.jmmm.2005.07.020

Cited by 66 publications

(20 citation statements)

References 42 publications

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“…The value decreases from 3.21 eV to 3.17 eV with nickel doping, which is in agreement with the reports [15,16] . The observed red shift in the band edge of the nickel doped ZnO nanoparticles is due to the increasing sp-d exchange interactions between the band electrons and the localized d-electrons of the Ni 2+ ions substituting Zn 2+ ions in the doped sample [17] .…”

Section: Fig5 ( H ) 2 Vs Photon Energy (H ) For Undoped and Nickel supporting

confidence: 93%

Synthesis and optical properties of Ni-doped zinc oxide nanoparticles for optoelectronic applications

Elilarassi

Chandrasekaran

2010

Optoelectron. Lett.

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Nanocrystalline undoped and nickel doped zinc oxide (Zn 1-x Ni x O, x = 0.00, 0.01) powders are successfully synthesized by a simple and low-temperature "auto-combustion method". The microstructural and optical absorption and emission properties of the as-prepared samples are obtained using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infra-red spectrometer (FTIR), UV-visible and photoluminescence (PL). The structure study confirms the formation of the hexagonal wurtzite ZnO without any secondary phase in the Ni-doped sample. The optical absorption measurements indicate the red shift in the absorption band edge upon nickel doping. The band gap energy decreases from 3.21 eV to 3.17 eV. The photoluminescence spectra of the as-prepared samples under a room temperature show strong ultraviolet (UV) and blue emission peaks. The PL emission research strongly reveals that Ni doping can effectively adjust the energy level which leads to a red shift at the emission peak in UV region.Nanocrystalline materials have attracted extensive attention due to their unique properties and immense potential applications in nanodevice fabrications [1][2][3][4] . ZnO is a wide band gap (3.34 eV) semiconductor material with high-exciton binding energy (60 meV) and higher optical gain than GaN at a room temperature [5,6] . ZnO is one of the promising materials for low-voltage and short-wavelength optoelectronic applications such as UV devices, light-emitting diodes and laser diode [7][8][9] . Its other applications include transparent ultraviolet protection films, gas sensors and varistors [10,11] . Though a wide research has been done on doped nanostructured materials, there are few reports on doped ZnO nanostructures, particularly about their optical properties. The transition metal doped nanostructure is an effective method to adjust the energy levels and surface states of ZnO, which can further introduce changes in its physical and especially optical properties [12] . In addition to the UV excitonic emission peak, ZnO commonly exhibits the visible luminescence at different emission wavelengths due to the intrinsic or extrinsic defects [13] .However, it is still a great challenge to synthesize ZnO nanostructures doped with the transition metal element using a simple process with a low cost. The solution growth method is an effective approach and promising route for synthesizing ZnO nanomaterials at a low temperature. Therefore, the solution growth "auto-combustion method" is used to prepare undoped ZnO and Ni-doped nanomaterials at a low temperature in this paper. The high quality nanocrystalline powders of Zn 1-x Ni x O (x=0.00, 0.01) are successfully synthesized and their structural and optical absorption and emission properties are investigated. The present synthesis method is reproducible and ensures the large scale production at a low temperature.All chemicals used are of analytical grade purity. In a typical synthesis of Zn 1-x Ni x O (x=0.00,0.01) samples, according to the appropriate proportion,...

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Section: Fig5 ( H ) 2 Vs Photon Energy (H ) For Undoped and Nickel supporting

confidence: 93%

Synthesis and optical properties of Ni-doped zinc oxide nanoparticles for optoelectronic applications

Elilarassi

Chandrasekaran

2010

Optoelectron. Lett.

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“…As for Co-doped ZnO polycrystalline, ferromagnetism with T C > 350 K was observed by Schwartz et al in aggregated nanocrystals of Co 2+ :ZnO [8]. RT ferromagnetic nanocrystalline Zn 0.9 Co 0.1 O powders have been synthesized by Maensiri et al [9] using polymerized complex method. However, no evidence of magnetic ordering in Co-doped polycrystalline ZnO was found down to T = 2 K [10].…”

Section: Introductionmentioning

confidence: 98%

Absence of room-temperature ferromagnetism in Al-codoped Zn0.95Co0.05O nanoparticles

Pei

Xia

et al. 2009

Journal of Alloys and Compounds

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“…Lately, ZnO-based diluted magnetic semiconductors (DMSs) have been of great interest because of some theoretical predictions of room temperature ferromagnetism [3]. So far, doping ZnO with transition metals like Co, Fe, Mn, Ni was usually employed in order to obtain ferromagnetic properties in ZnO [4][5][6][7][8][9][10][11][12]. However, the origin of the ferromagnetism is already controversial.…”

Section: Introductionmentioning

confidence: 99%

Magnetic and Electrical Properties of Undoped and Holmium Doped ZnO Thin Films Grown by Sol-Gel Method

Popa

Schmerber

Toloman

et al. 2013

AEF

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Abstract. Undoped and holmium-doped ZnO thin films were obtained, using the sol-gel method. The films were characterized by scanning electron microscopy (SEM), Hall effect measurements, electron paramagnetic resonance (EPR) spectroscopy and superconducting quantum interference device -vibrating sample magnetometry (SQUID-VSM). The Hall effect measurements have indicated a n-type conduction with a resistivity of about 3.2 Ω.cm for the undoped ZnO and of about 4.5 Ω.cm for the 5 at. % Ho-doped ZnO thin films. The EPR measurements have indicated the presence of interstitial zinc in the undoped ZnO and the presence of zinc vacancies in 5 at. % Ho-doped ZnO. Ho (5 at. %)-doped ZnO films exhibit superparamagnetism at 5 K, while a low paramagnetic behavior was observed at room temperature.

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Magnetic behavior of nanocrystalline powders of Co-doped ZnO diluted magnetic semiconductors synthesized by polymerizable precursor method

Cited by 66 publications

References 42 publications

Synthesis and optical properties of Ni-doped zinc oxide nanoparticles for optoelectronic applications

Synthesis and optical properties of Ni-doped zinc oxide nanoparticles for optoelectronic applications

Absence of room-temperature ferromagnetism in Al-codoped Zn0.95Co0.05O nanoparticles

Magnetic and Electrical Properties of Undoped and Holmium Doped ZnO Thin Films Grown by Sol-Gel Method

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