Optical and Magnetic Properties of Ni Doped ZnS Diluted Magnetic Semiconductors Synthesized by Hydrothermal Method

Abstract

Diluted magnetic semiconductors Zn 1− Ni S with different consistency ratio ( = 0, 0.01, 0.03, 0.05, and 0.07) were successfully synthesized by hydrothermal method using ethylenediamine as a modifier. The influence of Ni doping concentration on the microstructure, morphology, and optical and magnetic properties of undoped and Ni doped ZnS nanocrystals was characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray energy dispersive spectrometry (XEDS), ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FT-IR), photoluminescence spectra (PL), and the vibrating sample magnetometer (VSM), respectively. The experiment results show the substitution of Ni 2+ on Zn 2+ sites without changing the hexagonal wurtzite structure of ZnS and generate single-phase Zn 1− Ni S with good crystallization. The lattice constant causes distortion and decreases with the increase of Ni 2+ doped concentration. The appearance of the samples is one-dimensional well-dispersed nanorods. UV-vis spectra reveal the band gap of all Zn 1− Ni S samples greater than that of bulk ZnS (3.67 eV), and blue shift phenomenon occurs. The photoluminescence spectra of undoped and doped samples possess the broad blue emission band in the range of 400-650 nm; the PL intensities of Zn 1− Ni S nanorods increase with the increase of Ni content comparing to pure ZnS and reach maximum for = 0.03. Magnetic measurements indicated that the undoped ZnS samples are superparamagnetic, whereas the doped samples exhibit ferromagnetism.

Defect persuade paramagnetic properties of nickel doped ZnS nanocrystals and identification of structural, optical, local atomic structure

“…5. The polarization characteristics are identified by Raman spectroscopy with satisfactorily recognized indication of acoustic and optical modes [17,23]. There are two pronounced bands observed at 263 cm -1 and 347 cm -1 , which are identified as transverse optical (TO) and longitudinal optical (LO) modes, respectively.…”

“…The present observations implied that Ni dopant does not influenced on the lattice structure of nanocrystals and it corroborates with the TEM observations. However, it is observed that the Raman peaks are shifted toward lower energy (Table 2) as compared to the bulk ZnS values [23][24][25][26], which signify quantum confinement effects on synthesized Ni0 NCs and Zn Ni S x 1-x NCs. )…”

“…similar to scattering path (2.28 Å) of Ni0 sample. So, it has been concluded that lower dopant concentration do not affect the first co-ordination shell of the Zn atoms though their ionic radii are similar (Zn 2+ = 0.60 Å, Ni 2+ = 0.55 Å)[19][20][21][22][23].The quantitative comparison of absorption quality at the Ni K-edge (8331 eV), the normalized X-ray absorption near edge structure (XANES) spectrum of doped NCs samples including the Ni metal foil, standard NiS, and NiSO4 are performed to obtain oxidation state of nickel ions in…”

Synthesis and Characterization of ZnS Nanoparticles by Chemical Precipitation Method

“…The FTIR results showed several absorption bands in the region 4000 -400 cm -1 , the spectrum shows peaks at 415.585, 661.464, 1004.73, 1138.76,1629.55, and 3441.35 cm -1 . The peak at 3441.35 cm -1 and 1629.55 cm -1 related to OH groups that were surrounding around the nanoparticle, the peak at 3441.35 cm -1 related to OH stretching vibration, and the peak at 1629.55 cm -1 related to H-O-H bending (Sabaghi et al 2018), the peak at 1138.76 related to S-O impurities (Sabaghi et al 2018), the peak at 1004.73 may be corresponding to the organic compounds (Wu et al 2017), the peaks at 405 cm −1 and 661.464 cm -1 are the characteristic absorption of Zn-S bond (Shaikh and Sonawane. 2016), (Kumar and Upadhyay.…”

HRTEM, XPS and XRD characterization of ZnS/PbS nanorods prepared by thermal evaporation technique

“…For example, depending on the crystalline quality of the AlN substrate ZnO deposited films show an epitaxial growth [19,20]. Extensive studies have been reported on ZnS nanostructures doped with different transition metal ions (such as Co, Mn, Ni, Fe) prepared by different techniques [21][22][23][24]. Depending on the type of dopant ion, the doped materials exhibit different luminescent, electronic and magnetic properties.…”