Room temperature ferromagnetism in Mn doped ZnO: Co nanoparticles by co-precipitation method

2016 ◽  
Vol 481 ◽  
pp. 91-96 ◽  
Author(s):  
V. Pazhanivelu ◽  
A. Paul Blessington Selvadurai ◽  
Yongsheng Zhao ◽  
R. Thiyagarajan ◽  
R. Murugaraj
2013 ◽  
Vol 678 ◽  
pp. 234-238 ◽  
Author(s):  
Vishwanath D. Mote ◽  
Babasaheb N. Dole

Nanosized Mn doped ZnO samples were synthesized by co-precipitation method using Polyethylene glycol (PEG) as a capping agent. X- ray diffraction patterns confirm that the pure and Mn doped ZnO nanocrystals have wurtzite structure without any seconadary phases. Lattice parameters of pure and Mn doped ZnO nanocrystals increase slightly with increasing Mn concentration. The average crystalline size of pure and Mn doped ZnO nanocrystals are in the range of 14-18 nm. The X-ray density for pure and Mn doped ZnO sample is calculated using lattice parameters. It is found that almost static for Mn doped ZnO samples. In the Zn1-xMnx samples, room temperature magnetic hysteresis is observed and the saturation magnetization increases with increasing Mn content. However, these samples show room temperature ferromagnetic in nature. Result of the present investigation compared without PEG.


2006 ◽  
Vol 17 (5) ◽  
pp. 1278-1285 ◽  
Author(s):  
O D Jayakumar ◽  
H G Salunke ◽  
R M Kadam ◽  
Manoj Mohapatra ◽  
G Yaswant ◽  
...  

2010 ◽  
Vol 46 (6) ◽  
pp. 2152-2155 ◽  
Author(s):  
Yan Wu ◽  
K. V. Rao ◽  
Wolfgang Voit ◽  
Takahiko Tamaki ◽  
O. D. Jayakumar ◽  
...  

NANO ◽  
2016 ◽  
Vol 11 (04) ◽  
pp. 1650042 ◽  
Author(s):  
Majed Sharrouf ◽  
Ramadan Awad ◽  
Salem Marhaba ◽  
Douaa El-Said Bakeer

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.


2016 ◽  
Vol 487 ◽  
pp. 102-108 ◽  
Author(s):  
V. Pazhanivelu ◽  
A. Paul Blessington Selvadurai ◽  
R. Kannan ◽  
R. Murugaraj

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