Temperature and composition induced phase transitions in Sr2−xCa1+xTeO6 (0 ≤ x ≤ 2) double perovskite oxides

Tamraoui, Youssef; Manoun, Bouchaib; Mirinioui, F.; Saadoune, Ismae͏̈l; Haloui, R.; Elhachmi, A.; Saad, Elmadani; Lazor, Peter

doi:10.1016/j.molstruc.2016.11.036

Cited by 10 publications

(3 citation statements)

References 28 publications

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“…Vibrational studies were performed using a Raman spectrometer designed and built at the Department of Earth Sciences, Uppsala University 20 . Details of Raman spectroscopy experiment procedures are found elsewhere 21 . Raman spectra have been analyzed, with the peak-fitting function in origin software 22 .…”

Section: Raman Spectroscopymentioning

confidence: 99%

Structural, electronic, optical properties and first-principles calculations of Sr1-xCaxWO4 ceramics

Haddouch¹,

Tamraoui

Mirinioui

et al. 2019

Mediterr.J.Chem.,

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A series of strontium calcium tungstates Sr1-xCaxWO4 powders with (x = 0; 0.25; 0.5; 0.75 and 1.0) were prepared by solid-state reaction method and analyzed by X-ray diffraction (XRD). All these compositions possess a tetragonal scheelite structure with I41/a space group. Raman active vibrational modes in the range from 20 to 1000 cm-1 of the series Sr1-xCaxWO4 with tetragonal structure exhibit 13 modes in arrangement with the Group theory analysis of structural Raman-active modes. The optical properties were investigated using the diffuse reflectance UVâ€“visible absorbance spectrum. Based on Density Functional Theory (DFT) and using full Potential-linearized Augmented Plane Wave (FP-LAPW) method with the Local Density Approximation and the Generalized Gradient Approximation (GGA), implemented in the Wien2k package, we have investigated electronic and optical properties of all the compositions. The results indicate a decrease in the values of the optical direct bandgap (from 4.29 to 3.87 eV) with the increase of Ca into SrWO4 lattice, which is in good agreement with our experimental results.

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Section: Raman Spectroscopymentioning

confidence: 99%

Structural, electronic, optical properties and first-principles calculations of Sr1-xCaxWO4 ceramics

Haddouch¹,

Tamraoui

Mirinioui

et al. 2019

Mediterr.J.Chem.,

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“…The dielectric behaviour of Sr 2 CaTeO 6 has not yet been investigated and reported. In addition, the optical band gap, E opt , of this particular compound was reported to be at 2.75 eV, which can be associated with semiconducting character [15]. Hence, it is interesting to conduct a study on the dielectric properties of Sr 2 CaTeO 6 and understand its relation to its semiconducting character.…”

Section: Introductionmentioning

confidence: 99%

“…In 2005, Sr 2 CaTeO 6 , which applied both of these cations, was discovered and was found to crystallise in monoclinic P2 1 /n structure [13]. Most of the work on this compound was focused on structural or optical properties [14,15]. The dielectric behaviour of Sr 2 CaTeO 6 has not yet been investigated and reported.…”

Section: Introductionmentioning

confidence: 99%

Dielectric, AC Conductivity, and DC Conductivity Behaviours of Sr2CaTeO6 Double Perovskite

Halizan

Mohamed

2022

Materials

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Relatively new double perovskite material, Sr2CaTeO6, has been prepared through conventional solid-state procedures. Structural, dielectric, and optical characteristics of this exquisite solid-state material were analysed in this study. The single-phase monoclinic P21/n structure of this prepared compound was well correlated with the literature review. Good distribution of grain sizes and shapes was observed in the morphological study of this compound. The discussions on its optical and dielectric properties are included in this manuscript. High dielectric real permittivity, low dielectric loss, and good capacitance over a range of temperatures possessed by this compound, as shown in dielectric and electrical modulus studies, indicated good potential values for capacitor applications. The Ro(RgQg)(RgbQgb) circuit fitted well with the impedance and electrical modulus plot of the compound. Its relatively high electrical DC conductivity in grain at high frequencies and its increasing value with the temperature are typical of a semiconductor behaviour. This behaviour might be attributed to the presence of minor oxygen vacancies within its lattice structure and provides a long-range conduction mechanism. A small difference between activation energy and Ea of DC conductivity indicates that the same charge carriers were involved in both grains and the grain boundaries’ long-range conduction. The electrical AC conductivity of this compound was found to contribute to the dielectric loss in grain structure and can be related to Jonscher’s power law. The presence of polarons in this compound was exhibited by non-overlapping small polaron tunnelling (NSPT) and overlapping large polaron tunnelling (OLPT) conduction mechanisms over a range of temperatures. Wide optical band gap and Eopt in the range of 2.6 eV to 3.6 eV were determined by using an indirect and direct allowed mechanism of electrons transitions. These values supported the efficient semiconducting behaviour of the grain in this material and are suitable for applications in the semiconductor industry.

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On the structural phase transitions and optical properties of Sr2Sr1-xCaxTeO6 (0 ≤ x ≤ 1) ceramics

et al. 2021

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Temperature and composition induced phase transitions in Sr2−xCa1+xTeO6 (0 ≤ x ≤ 2) double perovskite oxides

Cited by 10 publications

References 28 publications

Structural, electronic, optical properties and first-principles calculations of Sr1-xCaxWO4 ceramics

Structural, electronic, optical properties and first-principles calculations of Sr1-xCaxWO4 ceramics

Dielectric, AC Conductivity, and DC Conductivity Behaviours of Sr2CaTeO6 Double Perovskite

On the structural phase transitions and optical properties of Sr2Sr1-xCaxTeO6 (0 ≤ x ≤ 1) ceramics

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