Effects of crystallization and microstructure on the dc electrical conductivity in the system xCuO–(70−x) MnO–30SiO2

Hammad, Ahmed H.; Abdel-Hameed, Salwa A.M.; Margha, Fatma H.

doi:10.1016/j.jallcom.2014.12.097

Cited by 10 publications

(7 citation statements)

References 27 publications

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“…Apart from the above discussed mechanism, analyses reported in literature indicated that electrical conduction appears to occur via a small-polaron hopping mechanism [45,46]. Similarly, in GCBCO, the small polaron hopping conduction unit Co 3?…”

Section: X-ray Photoelectron Spectroscopy Analysismentioning

confidence: 96%

Synthesis and conductivity properties of Gd0.8Ca0.2BaCo2O5+δ double perovskite by sol–gel combustion

Zhang

Lü

Wei

et al. 2015

J Mater Sci: Mater Electron

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Double perovskite oxides Gd 0.8 Ca 0.2 BaCo 2-O 5?d have been successfully prepared by EDTA-citrate complexation process. The prepared samples were characterized by means of thermogravimetry-differential analysis, X-ray diffraction, Fourier transform infrared spectroscopy techniques. These analyses suggested that pure Gd 0.8 Ca 0.2 BaCo 2 O 5?d phase could be formed when the pH value was maintained above three and calcination temperature was higher than 850°C. The conductivity properties analyzed by means of four probes method, scanning electron microscopy and X-ray photoelectron spectroscopy indicated an improvement in conductivity with a high value of nearly 1200 S/cm, which was due to an increase in the number of small polaron hopping conduction units, Co 3? -O-Co 4? . Interestingly, the Gd 0.8-Ca 0.2 BaCo 2 O 5?d samples exhibited a semiconducting behavior through a wide range of temperature below 100°C and a metallic behavior at 100-500°C, thereby demonstrating that Gd 0.8 Ca 0.2 BaCo 2 O 5?d could meet the requirements of a smart material.

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Section: X-ray Photoelectron Spectroscopy Analysismentioning

confidence: 96%

Synthesis and conductivity properties of Gd0.8Ca0.2BaCo2O5+δ double perovskite by sol–gel combustion

Zhang

Lü

Wei

et al. 2015

J Mater Sci: Mater Electron

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“…Optical absorption, particularly the absorption edge, is useful for the investigation of optically-induced transitions and for getting information about the band gap energy [4,10,11,14,16,37,41]. This parameter is very interesting for the applications of the materials to be studied.…”

Section: Uv-vis Spectroscopymentioning

confidence: 99%

“…• n: a constant which determines the type of the optical transition. For direct allowed transition n = 2 and in the case of indirect allowed transition n= 1 2 [4,10,11,14,16,37,41].…”

Section: αν ðþ¼mentioning

confidence: 99%

“…For glassy materials, the indirect transitions are valid according to Tauc relations [4,10,11,14,16,37,41]. Figure 4 represents the variation (αhν) 2 versus photon energy (hν) for (0.9-x) NaPO 3 -xSiO 2 -0.1ZnO (0 ≤ x ≤ 0.1 mol) series glasses.…”

Section: αν ðþ¼mentioning

confidence: 99%

“…Figure 5 shows clearly that the E opt values dependent strongly on the composition of the glass also on the oxygen bonding in the vitreous network [4,10,11,14,16,37,41]. Any changes of oxygen bonding suggesting the formation of nonbridging oxygen (NBOs) causes a change of the absorption characteristics of the glass [4,10,11,14,16,37,41].…”

Section: αν ðþ¼mentioning

confidence: 99%

See 2 more Smart Citations

Structural and Calorimetric Studies of Zinc, Magnesium and Manganese Based Phosphate and Phosphate-Silicate Glasses

Omrani¹,

Jemal²,

Khattech³

et al. 2020

Contemporary Topics About Phosphorus in Biology and Materials

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Glasses of the (50-x/2)Na 2 O-xMO-(50-x/2)P 2 O 5 (M = Zn, Mg or Mn) (0 ≤ x ≤ 33 mol%), (50-x)Na 2 O-xMO-50P 2 O 5 (M = Zn, Mn) (0 ≤ x ≤ 33 mol%), and (0.9-x) NaPO 3 -xSiO 2 -0.1ZnO (0 ≤ x ≤ 0.1 mol) were prepared by the melt quenching technique. Samples were investigated by means of X-ray diffraction, Archimede's method, ellipsometry, Fourier-transformed infrared (FTIR), Raman, 31P solid state magic angle spinning nuclear magnetic resonance (MAS-NMR), UV-visible spectroscopy and calorimetry. For zinc, manganese and magnesium phosphate glasses, the increase in density with the addition of MO oxide suggests the compactness of the vitreous network. For zinc phosphate silicate glasses, the variations of density and refractive index were attributed to the structural changes when SiO 2 oxide is progressively introduced. The increase in the glass transition temperature (Tg) reflects an increase in the cross-link strength of the structure as MO and SiO 2 oxides are gradually incorporated. For all glass composition, spectroscopic investigations revealed the depolymerization of metaphosphate chains (Q 2 ) allowing the formation of phosphate dimers (Q 1 ). Calorimetric dissolution shows that the dissolution is endothermic for lower MO content and become exothermic when x rises. For (50-x/2)Na 2 O-xZnO-(50-x/2)P 2 O 5 (0 ≤ x ≤ 33 mol%) glasses, the formation enthalpy increases with the incorporation of ZnO oxide.

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Preparation, crystallization and electrical properties of 35CuO·(35 − X)MnO·XBi2O3·30SiO2 system (X = 0–20 mol%)

Abdel-Hameed

Morsi

Margha

2016

J Mater Sci: Mater Electron

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Effects of crystallization and microstructure on the dc electrical conductivity in the system xCuO–(70−x) MnO–30SiO2

Cited by 10 publications

References 27 publications

Synthesis and conductivity properties of Gd0.8Ca0.2BaCo2O5+δ double perovskite by sol–gel combustion

Synthesis and conductivity properties of Gd0.8Ca0.2BaCo2O5+δ double perovskite by sol–gel combustion

Structural and Calorimetric Studies of Zinc, Magnesium and Manganese Based Phosphate and Phosphate-Silicate Glasses

Preparation, crystallization and electrical properties of 35CuO·(35 − X)MnO·XBi2O3·30SiO2 system (X = 0–20 mol%)

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