Eurasian Journal of Physics and Functional Materials

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Vol 7, No 2 (2023)
79-90 463

The phase composition of several fragments of the ancient ceramic of the early medieval settlement of Asusay and burial ground Eleke Sazy in the modern Republic of Kazakhstan has been studied using neutron diffraction and Raman spectroscopy. The quartz, calcite, and feldspar minerals are dominant phases in the studied ceramic fragments. The fractions of those phases were obtained. The spatial arrangement of inner components inside volumes of fragments was determined using neutron tomography. The pores in the ceramic fragments were segmented, and the porosity for each sample was obtained. The phase composition and internal pores are discussed within the framework of the structural indicators of local clay sources and features of ancient pottery technologies.

91-106 357

(1-x)[(Pb0.94Sr0.05La0.01)(Zr0.54Ti0.46)0.9975O3]-x[Bi(Mn 1/2 Ti1/2 )O3] ceramics with x in the range of 0–0.05 mol were successfully synthesized following the conventional solid-phase route. The materials were thoroughly investigated to study their structural phase, microstructure, ferro-piezoelectric characteristics, and dielectric behavior. The addition of BMT to PSLZT contributed to the transition of the tetragonal phase to the rhombohedral phase and an increase in the mechanical quality coefficient Qm of the material. The value of the electromechanical coupling coefficient kp =0.66, the value of kt=0.53, the value of the piezoelectric constant d33 =643 pC/N was obtained in the undoped PSLZT ceramics. The component 0.97PSZT–0.03BMT exhibited properties similar to those of hard piezoelectric ceramics. The electromechanical coupling factor kp was calculated to be 0.59, the value of kt was calculated to be 0.48, the piezoelectric constant d33 was calculated to be 446 pC/N, the mechanical quality factor Qm was found to be 774 and the phase transition temperature Tm was calculated to be 265 ◦ C. The ceramic component shows promise for use in practical power ultrasonic applications.

107-114 248

The article presents data on the study of the effect of substitutions of M-cations in the system of Na3Fe2(1-x)Sc2x(PO4)3 solid solutions (in the concentration range 0≤x≤0.06) on the crystal structure, ionic conductivity, and also on the temperature of phase transitions Ta→b, Tb→g. It is shown that samples of Na3Fe2(1-x)Sc2x(PO4)3 (0≤x≤0.06) solid solutions are monoclinically distorted, and the structure parameters increase linearly with increasing dopant concentration. Moreover, in the studied samples of solid solutions, an increase in the conductivity of the a -phase and a decrease in the b - and g -phases are observed, as well as a decrease in the temperatures Ta→b and Tb→g. It is concluded that these changes are associated with both local deformations of the anionic part of the crystalline structure, and violation of the regularity of the crystal structure

115-122 320

The Na2SO4 − Dy samples were obtained by slow evaporation method. The spectroscopic methods were used to study the mechanisms of formation of electron and hole trapping centers. Intrinsic recombination emission of 2.9–3.1 eV and impurity emission of 2.55 eV and 2.15 eV are excited at 4.0–4.5 eV. Intrinsic SO3−4− SO4 and impurity Dy2+−SO4 trapping centers were revealed. The local levels corresponding between the electron and hole trapping center are 4.0–4.5 eV.

123-132 299

The article presents a comprehensive review of the current research on the use of surfactants in CdTe nanoplatelet synthesis, including a discussion of the various types of surfactants that have been used and their effects on nanoplatelet size, shape, and optical properties. Additionally, the article examines the mechanisms by which surfactants influence the growth and morphology of CdTe nanoplatelets, with a focus on the role of surfactant, size, and structure. Overall, this article provides a detailed analysis of the use of surfactants in the synthesis of CdTe nanoplatelets and highlights the potential for this approach to improve the performance of CdTe-based technologies. The dependences of the NPL absorption and photoluminescence spectra on acids used as surfactants are shown. The dependence of the shape and size of the NPL on the length of the surfactant ligand was found.

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ISSN 2522-9869 (Print)
ISSN 2616-8537 (Online)