Thermodynamic and Electrophysical Properties of La2SrNiTeO7

Рустембеков, К. Т.; Kasenov, B. K.; Bekturganova, A. Zh.; Kasymova, M. S.

doi:10.1134/s0036024419090206

Cited by 4 publications

(3 citation statements)

References 3 publications

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“…As a rule, the temperature dependence of electrophysical properties is observed in ceramic ferroelectrics. The observed anomalous jumps on the curves of the temperature dependence of the resistance of the compounds indicate Type II phase transitions, conditioned by the semiconductor and ferroelectric properties of the new double samarium tellurites [11][12][13]. It is known that an abrupt transition is accompanied by a structure that provides an anomalously fast three-dimensional diffusion of cations [14].…”

Section: Resultsmentioning

confidence: 99%

New Samarium Oxotellurites: Synthesis and Characteristic

Toibek¹,

Rustembekov²,

Fomin³

et al. 2023

Eurasian J. Chem.

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We synthesized samarium oxotellurites SmMTeO4.5 (M — Mg, Ba) by the method of ceramic technology with solid-phase interaction (800–1200 °С) of Sm2O3 and TeO2 oxides with MgCO3 and BaCO3 carbonates. The compounds were characterized by X-ray and electrophysics methods. It has been established that the syn-thesized compounds crystallize in the tetragonal syngony with the following crystallographic characteristics: SmMgTeO4.5 — a = 12.226; c = 5.783 Å, V0un.cell = 864.38 Å3, Z = 4, ρxray. = 2.876, ρpycn. = (2.874±0.002) g∙cm-3; SmBaTeO4.5 — a = 12.717; с = 6.132Å, V0un.cell = 991.62Å3, Z = 4, ρxray. = 3.264, ρpycn. = (3.260±0.004) g∙cm-3; for both tellurites α = β = γ = 90°. The experimental and calculated values of 2 Th and d-sp, X-ray and pycnometric densities, as well as theoretical and experimental values of unit cell volumes are agreed satisfac-torily. Thus, we can confirm correctness and reliability of the results of indexing X-ray patterns of new sa-marium oxotellurites. We found that increase in the ionic radii from Mg to Ba increases the lattice parameters of the synthesized oxotellurites. Oxotellurites are crystallized in the structural types of distorted perovskite Pm3m. Based on the given study samarium oxotellurites can have semiconductor and ferroelectric properties.

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Section: Resultsmentioning

confidence: 99%

New Samarium Oxotellurites: Synthesis and Characteristic

Toibek¹,

Rustembekov²,

Fomin³

et al. 2023

Eurasian J. Chem.

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“…The accuracy of electrical capacitance and electrical resistance measurements, according to the instrument's data sheet is ± 0.05% [20]. Similar studies were carried out earlier in [24,25]. It is known that, as a rule, there is a temperature dependence of the electro-physical properties in ceramic ferroelectrics.…”

Section: Electro-physical Propertiesmentioning

confidence: 93%

SYNTHESIS AND PROPERTIES OF NdMe<sup>II</sup>TeO4.5 (MeII – Ca,Ba) TELLURITES

Rustembekov,

Toibek,

Stoev

et al. 2024

JCTM

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The aim of this work was to synthesize and investigate the roentgenographic and electro-physical properties of new phases, namely double tellurites of neodymium. Oxotellurites of the composition NdMeIITeO4.5(MeII - Ca, Ba) were synthesized by the method of ceramic technology with high-temperature interaction of Nd2O3, TeO2 oxides with carbonates of alkaline earth metals in the interval of 800°С - 1200°С. Roentgenograms of the synthesized compounds were obtained using an Empyrean powder diffractometer by PANalytical and indication was determined using the X’Pert HighScore Plus program. It was found that the synthesized tellurites were crystallized in tetragonal syngony. The unit cell parameters, roentgen and pycnometric densities of the compounds were determined. It was revealed that with increasing ionic radii from Ca to Ba, the lattice parameters and unit cell volumes of synthesized tellurites increase. The assumed structure of the synthesized double tellurites of neodymium is a distorted perovskite structure. A study of the temperature dependence of the dielectric permittivity and electrical resistance of tellurites of neodymium-alkaline earth metals established that they can possess semiconducting properties at 293 K - 483 K. Temperature coefficients of resistance and forbidden zone width of tellurites were calculated.

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“…X-ray diffraction data shows that synthesized tellurites crystallize in the structural types of distorted perovskite Pm3m. It allows supposing that these compounds can have unique electrophysical properties [9][10][11][12].…”

Section: Compoundmentioning

confidence: 99%

Synthesis and properties of double gadolinium tellurites

Toibek¹,

Rustembekov²,

Kaikenov³

et al. 2021

Bull. of the Kar. Univ. "Chem". Ser.

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For the first time, double gadolinium tellurites of the composition GdMIITeO4.5 (MII — Sr, Ba) were synthesized by the solid-phase method. The solid-phase synthesis of samples was carried out from decrepitated gadolinium (III) and tellurium (IV) oxides, strontium, and barium carbonates according to the standard ceramic technology. The synthesis was carried out in the temperature range of 800-1100 °C. The samples obtained were confirmed by X-ray phase analysis. X-ray phase analysis was carried out on an Empyrean instrument in the XRDML Pananalitical format. The intensity of the diffraction maxima was estimated on a 100-point scale. X-ray diffraction patterns indexing of the powder of gadolinium tellurites — alkaline earth metals studied were carried out by the homology method. The reliability and correctness of the results of indexing the X-ray diffraction patterns are confirmed by the good agreement between the experimental and calculated values of the interplanar distances (d) and the agreement between the values of the X-ray and pycnometric densities. It was found that compounds GdSrTeO4.5 and GdBaTeO4.5 crystallize in the monoclinic system and have the unit cell parameters, namely GdSrTeO4.5 — a = 12.7610, b = 10.4289, c = 8.6235 Å, V° = 1141.83 Å3, β = 95.77°, Z = 5, ρrent. = 3.22, ρpikn. = (3.10±0.09) g/cm3; GdBaTeO4.5 — a = 15.7272, b = 15.8351, c = 7.1393 Å, V° = 1769.72 Å3, β = 95.53°, Z = 8, ρrent = 3.71, ρpick = (3.61±0.10) g/cm3. Using the Landiya method, the standard heat capacities of the compounds were estimated from the calculated values of the standard entropies, and the temperature dependences of the heat capacities of the gadolinium tellurites synthesized were determined in the temperature range of 298–850 K.

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Thermodynamic and Electrophysical Properties of La2SrNiTeO7

Cited by 4 publications

References 3 publications

New Samarium Oxotellurites: Synthesis and Characteristic

New Samarium Oxotellurites: Synthesis and Characteristic

SYNTHESIS AND PROPERTIES OF NdMe<sup>II</sup>TeO4.5 (MeII – Ca,Ba) TELLURITES

Synthesis and properties of double gadolinium tellurites

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