Structural and frequency dependent dielectric properties of Fe3+ doped ZnO nanoparticles

Hassan, Mohammed; Ahmed, Arham S.; Chaman, M.; Khan, Wasi; Naqvi, Andleeb Z.; Azam, Ameer

doi:10.1016/j.materresbull.2012.08.015

Cited by 140 publications

(13 citation statements)

References 47 publications

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“…For a given frequency, the conductivity decreases with the increase of Samarium doping due the reduction in the concentration of intrinsic donors leading to the cease of the hopping mechanism between Zn 2+ and Sm 3+ ; consequently, the n-type conductivity of host ZnO decreases [68]. Figures 10(a) and (b) represent the temperature dependence of dielectric constant ε′ and ac conductivity σ ac at f=500 KHz for x=0.01, 0.02 and 0.06.…”

Section: Dielectric Studiesmentioning

confidence: 99%

The investigation of mechanical and dielectric properties of Samarium doped ZnO nanoparticles

Badreddine

Srour

Awad

et al. 2020

Mater. Res. Express

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Zn1−xSmxO nanoparticles, with 0.00 ≤ x ≤ 0.10, were prepared using chemical co-precipitation method. The structure and morphology of the obtained samples were characterized using x-ray powder diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM), respectively. However, the mechanical properties were investigated via digital Vickers microhardness tester. Vickers microhardness measurements were carried out at different applied loads, varying between 0.5 and 10 N at dwell time 60 s on pressed discs of average thickness 3 mm. Hv decreased as the Sm-content increased up to 0.02 and then it increased for higher concentrations. Whereas, it increased as the applied load increased, revealing that the samples exhibited a reverse indentation size effect (ISE). The microhardness measurements were interpreted using various models such as Meyer’s law, Hays and Kendall (HK) approach, elastic/plastic deformation (EPD), proportional specimen resistance (PSR) and the indentation-induced cracking (IIC). Mechanical parameters such as Young’s modulus (E), yield strength (Y), fracture toughness (K) and brittleness index (B) were calculated as a function of x. The most adequate model for the true microhardness of these samples is IIC. It was found that the addition of Sm content enhanced the mechanical properties of the prepared samples after x = 0.02. Dielectric measurements were used to compute different parameters such as real and imaginary parts of the complex permittivity, dielectric loss (tan δ) and ac conductivity (σ ac).

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Section: Dielectric Studiesmentioning

confidence: 99%

The investigation of mechanical and dielectric properties of Samarium doped ZnO nanoparticles

Badreddine

Srour

Awad

et al. 2020

Mater. Res. Express

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“…The discussion on zinc and oxygen vacancies largely diverges in the literature: a number of studies support the idea that the zinc vacancies are responsible for charge compensation in Fe-doped ZnO [11,25,47]; however, it has also been suggested that oxygen vacancies can play a role in charge compensation [48]. Nonetheless, the discussion is still ongoing, and in some cases it is reported that ferromagnetism may be induced by defects in such vacancies [49].…”

Section: Resultsmentioning

confidence: 99%

Local coordination of Fe³⁺in ZnO nanoparticles: multi-frequency electron paramagnetic resonance (EPR) and Newman superposition model analysis

Açıkgöz

Drahus

Ozarowski

et al. 2014

J. Phys.: Condens. Matter

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Iron-doped ZnO nanoparticles have been synthesized through high-energy ball milling of powders produced by the co-precipitation method. Fine particles with an average size down to 40 nm have been obtained after 15 min of milling. Fe(3+) cations have been incorporated into the ZnO lattice within the limits of the solubility. By using multi-frequency and high-field electron paramagnetic resonance (EPR) we have resolved all electronic transitions for the S = 5/2 high-spin system and have accurately determined the EPR spin-Hamiltonian parameters. By combining data from crystallographic x-ray diffraction and EPR with the semi-empirical Newman superposition model we have found the local configurational position of Fe(3+) and have confirmed the symmetry of the lattice. Results presented in this paper indicate that Fe cations most probably substitute at Zn-sites in ZnO. At nanosizes the effect of Fe(3+) cations on the surface becomes remarkable: additional size effects can be observed in the EPR spectrum, which are different from the spectrum of bulk.

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“…The loss of electrical energy in the dielectric material is described by the term dissipation factor tan δ = Z'/Z" [47], where δ is the phase difference between the material's induced current and the applied field. Fig.…”

Section: Dielectric Analysismentioning

confidence: 99%

“…where temperature and material intrinsic properties affect the coefficient B and the exponent n; B denotes conductivity units, while n is a dimensionless quantity [47]. To evaluate whether the conduction is frequency-independent (n = 0) or frequency-dependent (0 < n < 1) [56], the numerical value of n is calculated from the slope of the log σac vs. log f .…”

Section: Dielectric Analysismentioning

confidence: 99%

Structure, Optical, and Dielectric Properties of Cu1-xAgxAlO2 Nanoparticles

Saleh¹,

Albarg²

2023

Preprint

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The solid-state technique was utilized to make a single phase of delafossite CuAlO2, along with 1%, 2%, 3% and 4% silver doped CuAlO2 samples in this study. The content of the samples was investigated using energy dispersive X-ray spectroscopy (EDS) equipped with a field emission scanning electron microscope (FE-SEM). The polycrystalline nature of all of the analyzed cases was confirmed by structural analyses utilizing an X-ray diffraction (XRD) pattern with a simple typical peak of CAO rhombohedral phase. Raman, FT-IR and UV–Vis spectroscopy were used to study the structural, and optical energy band gap (Eg) of Ag doped CuAlO2 nanoparticles. The Kubelka–Munk function was used to calculate the optical band gap of ACAO alloys using diffuse reflectance spectra, and it altered as the Ag ion concentration increased. A. c. impedance spectroscopy was used to investigate the dielectric characteristics of Ag doped CuAlO2 nanoparticles.

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Structural and frequency dependent dielectric properties of Fe3+ doped ZnO nanoparticles

Cited by 140 publications

References 47 publications

The investigation of mechanical and dielectric properties of Samarium doped ZnO nanoparticles

The investigation of mechanical and dielectric properties of Samarium doped ZnO nanoparticles

Local coordination of Fe³⁺in ZnO nanoparticles: multi-frequency electron paramagnetic resonance (EPR) and Newman superposition model analysis

Structure, Optical, and Dielectric Properties of Cu1-xAgxAlO2 Nanoparticles

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Structural and frequency dependent dielectric properties of Fe3+ doped ZnO nanoparticles

Cited by 140 publications

References 47 publications

The investigation of mechanical and dielectric properties of Samarium doped ZnO nanoparticles

The investigation of mechanical and dielectric properties of Samarium doped ZnO nanoparticles

Local coordination of Fe3+in ZnO nanoparticles: multi-frequency electron paramagnetic resonance (EPR) and Newman superposition model analysis

Structure, Optical, and Dielectric Properties of Cu1-xAgxAlO2 Nanoparticles

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Local coordination of Fe³⁺in ZnO nanoparticles: multi-frequency electron paramagnetic resonance (EPR) and Newman superposition model analysis