Chimica Techno Acta最新文献_第4页

Comparative characteristic of Bi- and La- doped (Ca/Sr)MoO4 -based materials with a defect scheelite-type structure 具有白钨矿缺陷型结构的掺杂(Ca/Sr)MoO4（Bi 和 La）基材料的比较特性

Chimica Techno Acta Pub Date : 2023-12-06 DOI: 10.15826/chimtech.2023.10.4.11

Z. Mikhaylovskaya, A. V. Klimova, Sofia A. Petrova, E. Pankrushina, E. S. Buyanova

{"title":"Comparative characteristic of Bi- and La- doped (Ca/Sr)MoO4 -based materials with a defect scheelite-type structure","authors":"Z. Mikhaylovskaya, A. V. Klimova, Sofia A. Petrova, E. Pankrushina, E. S. Buyanova","doi":"10.15826/chimtech.2023.10.4.11","DOIUrl":"https://doi.org/10.15826/chimtech.2023.10.4.11","url":null,"abstract":"CaMoO4- and SrMoO4-based scheelite-type phases are noteworthy functional materials, whose properties strongly correlate with their structure. This work is devoted to La- or Bi-doped scheelite-type molybdates. The purpose of the present study is to quantify the effect of isolated electron pairs of bismuth on the distortion of the structure and related properties. Conventional solid-state technology was used for the synthesis of (Ca/Sr)1–3xLa2xФxMoO4 and Sr1–3xBi2xФxMoO4, (0.025≤ x ≤ 0.275). The structure was investigated by X-ray powder diffraction and Raman spectroscopy. Rates of structure distortion were characterised by the analysis of the autocorrelation function (AAF) of Raman spectra. Energy gaps were calculated by the Kubelka-Munk method. The conductivity was studied with a.c. impedance spectroscopy. For (Ca/Sr)1−3x(Bi/La)2xФxMoO4 series 0.025 ≤ x ≤ 0.15 compositions show a basic defect scheelite structure, while 0.15 x ≤ 0.225 compositions of Bi-doped samples exhibit tetragonal supercells. The chemical compression of unit cell is more evident in the case of Bi-doping, indicating the preferred orientation of the isolated electron pairs. The distortion of MoO4 polyhedra showed by AAF was more significant for Sr1−3xBi2xФxMoO4 than for Sr1−3xLa2xФxMoO4, the Δcorr parameters for Bi-doped compositions were almost double in comparison with La-doped one in the range of 50–600 cm–1 of the Raman shift. The «critical» x = 0.15 point was also clearly indicated by Δcorr parameter. The AAF of the Raman spectra of solid oxides was shown to be a good tool for prediction of properties and points of phase transitions in solid oxides.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":"40 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138597834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Towards nanomaterials with tubular pores: synthesis and self-assembly of bis-pillar[5]arene 开发具有管状孔隙的纳米材料：双柱[5]炔的合成与自组装

Chimica Techno Acta Pub Date : 2023-12-06 DOI: 10.15826/chimtech.2023.10.4.12

D. Shurpik, Yulia I. Aleksandrova, Lyaysan I. Makhmutova, Alan Akhmedov, Ivan I. Stoikov

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Acknowledgment of Chimica Techno Acta’s reviewers for 2023 2023 年 Chimica Techno Acta 杂志审稿人致谢

Chimica Techno Acta Pub Date : 2023-11-28 DOI: 10.15826/chimtech.2023.10.4.e

Dmitry A. Medvedev

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Features of forming a low-temperature cubic Li7La3Zr2O12 film by tape casting 通过胶带浇铸形成低温立方 Li7La3Zr2O12 薄膜的特点

Chimica Techno Acta Pub Date : 2023-11-21 DOI: 10.15826/chimtech.2023.10.4.09

E. Lyalin, Larisa Pershina, Evgeniy a Il’ina, Konstantin Druzhinin, Semen Belyakov

{"title":"Features of forming a low-temperature cubic Li7La3Zr2O12 film by tape casting","authors":"E. Lyalin, Larisa Pershina, Evgeniy a Il’ina, Konstantin Druzhinin, Semen Belyakov","doi":"10.15826/chimtech.2023.10.4.09","DOIUrl":"https://doi.org/10.15826/chimtech.2023.10.4.09","url":null,"abstract":"Currently, interest to lithium and lithium-ion all-solid-state power sources is rapidly growing all over the world. However, several issues should be addressed before all-solid-state batteries production: high resistance values of the solid electrolyte membrane and poor contact between electrolyte and electrode materials. The transition to thin-film technologies is one of the promising ways to solve these problems. Tape casting can be proposed to obtain thin-film solid electrolytes. In this research, the features of the structure formation, morphology and lithium-ion conductivity of Li7La3Zr2O12 films were investigated. Li7La3Zr2O12 films with the thickness of 35 µm were obtained by tape casting on Ni substrate. The influence of organic components’ content on homogeneous coatings formation was established. Heat treatment conditions for dried films were chosen based on differential scanning calorimetry and optical dilatometry. Phase change from tetragonal to low-temperature cubic modification occurs after annealing the Li7La3Zr2O12 films at 700 °C and higher. The annealed Li7La3Zr2O12 films have developed surface, which can lead to improved contact between the solid electrolyte and an electrode in an electrochemical cell. Li7La3Zr2O12 films annealed at 800 °C have the highest lithium-ion conductivity values (2.5·10–7 and 1.5·10–5 S·cm–1 at 90 and 215 °С, respectively). The technology of Li7La3Zr2O12 films formation with the thickness of ~23 µm by tape casting was developed.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":"96 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139254557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Kinetics of nitric acid leaching of bornite and chalcopyrite 用硝酸浸出辉锑矿和黄铜矿的动力学原理

Chimica Techno Acta Pub Date : 2023-11-16 DOI: 10.15826/chimtech.2023.10.4.10

Yuri Shklyaev, O. Dizer, Tatyana Lugovitskaya, D. Golovkin, Denis Rogozhnikov

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Colloid-chemical properties of surfactant–nitric acid–water systems 表面活性剂-硝酸-水体系的胶体-化学特性

Chimica Techno Acta Pub Date : 2023-11-03 DOI: 10.15826/chimtech.2023.10.4.08

Lev Danilin, Tatyana Lugovitskaya, Elvira Kolmachikhina, Denis Rogozhnikov

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Facile synthesis of lanthanum-doped SrTiO₃ nanocubes mediated by cetyltrimethylammonium bromide and tert-butylamine under solvothermal condition and their tunable electrical properties 溶剂热条件下十六烷基三甲基溴化铵和叔丁胺介导的镧掺杂SrTiO3纳米立方的快速合成及其可调电学性能

Chimica Techno Acta Pub Date : 2023-10-26 DOI: 10.15826/chimtech.2023.10.4.07

Yulia Eka Putri, Humaira Faradilla, Dedi Satria, Diana Vanda Wellia

{"title":"Facile synthesis of lanthanum-doped SrTiO<sub>3</sub> nanocubes mediated by cetyltrimethylammonium bromide and tert-butylamine under solvothermal condition and their tunable electrical properties","authors":"Yulia Eka Putri, Humaira Faradilla, Dedi Satria, Diana Vanda Wellia","doi":"10.15826/chimtech.2023.10.4.07","DOIUrl":"https://doi.org/10.15826/chimtech.2023.10.4.07","url":null,"abstract":"The electrical conductivity of low concentrations of lanthanum-doped SrTiO3 nanocube ceramics synthesized using the facile solvothermal method in mixed organic and inorganic solvents with cetyltrimethylammonium bromide (CTAB) as a capping agent and tert-butyl amine (TBA) as a mineralizer was investigated. X-ray diffraction patterns confirmed the formation of a high-purity perovskite phase, corresponding to the standard data and the pattern refinement results. The particles of the sample were nanocubes, whereas the La-doped SrTiO3 sample particles were more uniform in size and shape, as shown in TEM images. The FT-IR spectrum confirmed the vibration of the CH3-N+ groups from CTAB and TBA, indicating an electrostatic interaction between their functional groups and the particle surface. Substitution of La3+ ions at low concentrations increased electrical conductivity compared to the undoped SrTiO3 sample. Lanthanum donates excess electrons, thereby increasing the number of electron carriers, which causes a reduction in the band gap energy according to the UV-DRS spectrum analysis using the Tauc equation.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":"20 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135013353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Corrigendum to The impact of dimethylformamide on the synthesis of graphene quantum dots derived from graphene oxide 二甲基甲酰胺对由氧化石墨烯衍生的石墨烯量子点合成的影响的更正

Chimica Techno Acta Pub Date : 2023-10-26 DOI: 10.15826/chimtech.2023.10.4.06

Khuong T. Truong, Thach H. Pham, Khai V. Tran

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Features of calcium hexaaluminate formation in alumina-zirconia ceramics 氧化铝-氧化锆陶瓷中六铝酸钙形成的特征

Chimica Techno Acta Pub Date : 2023-10-26 DOI: 10.15826/chimtech.2023.10.3.17

Nina Cherkasova, Kristina Antropova, Ruslan Kuzmin, Kemal Emurlaev, Ivanna Kuchumova, Nomina Burkhinova, Yulia Zobova

{"title":"Features of calcium hexaaluminate formation in alumina-zirconia ceramics","authors":"Nina Cherkasova, Kristina Antropova, Ruslan Kuzmin, Kemal Emurlaev, Ivanna Kuchumova, Nomina Burkhinova, Yulia Zobova","doi":"10.15826/chimtech.2023.10.3.17","DOIUrl":"https://doi.org/10.15826/chimtech.2023.10.3.17","url":null,"abstract":"Alumina-zirconia composites containing calcium hexaaluminate in the amount from 0 to 15 wt.% were investigated. The materials were obtained by water dispersion, granulation, axial pressing, and free sintering. Density and open porosity were determined by the hydrostatic weighing method. Phase analysis was performed using synchrotron radiation. Structural investigations were conducted using scanning and transmission electron microscopy. Vickers hardness was determined at a load of 10 kg. Fracture toughness was determined by the indentation method. With increasing CaAl12O19 content in the composites, the relative density decreased from 98.5% to 91.8%, and the open porosity increased from 0.2 to 1.4%. The lattice parameters of t-ZrO2 crystal lattice did not change up to 12 wt.% CaAl12O19, and the degree of tetragonality was 1.435. The degree of tetragonality decreased for the material with 15 wt.% CaAl12O19 and reached 1.420. The lattice parameters of CaAl12O19 decreased with increasing content. Platelet size increased with increasing calcium hexaaluminate content. For the materials containing up to 9 wt.% CaAl12O19, the average length of the platelets was 2 μm, the width was 0.4 μm, and the aspect ratio was 5. For the material with maximum calcium hexaaluminate content, the average length of the platelets was 4.2 μm, the width was 0.6 μm, and the aspect ratio was 7. With increasing CaAl12O19 content, the hardness decreased from 1700±25 to 1390±30 Hv, and the critical stress intensity factor increased by 34% to 6.7±0.3 MPa·m1/2.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":"61 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134907264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Influence of the powders phase composition and sintering atmosphere on the structure and magnetic properties of Mn-Zn ferrites 粉末相组成和烧结气氛对Mn-Zn铁氧体结构和磁性能的影响

Chimica Techno Acta Pub Date : 2023-10-23 DOI: 10.15826/chimtech.2023.10.3.16

Ruslan Kuzmin, Roman Khabirov, Anna Mass, Elena Lozhkina

{"title":"Influence of the powders phase composition and sintering atmosphere on the structure and magnetic properties of Mn-Zn ferrites","authors":"Ruslan Kuzmin, Roman Khabirov, Anna Mass, Elena Lozhkina","doi":"10.15826/chimtech.2023.10.3.16","DOIUrl":"https://doi.org/10.15826/chimtech.2023.10.3.16","url":null,"abstract":"The magnetic properties of Mn-Zn ferrites depend strongly on the microstructure, chemical and phase composition. In this paper the effect of synthesis and sintering conditions on the structure, phase composition and properties of Mn-Zn ferrites is investigated. The specimens for the study were obtained by pressureless sintering. The magnetic properties were measured on a B-H analyzer. The structure was investigated by XRD and SEM. Materials with an average grain size of 2.2 μm were obtained by sintering at a temperature of 1265 °C. It was found that an increase in the synthesis temperature from 700 to 1000 °C promotes the growth of the initial magnetic permeability of these materials from 1100 to 1370. The rapid cooling of the powders synthesized at 1000 °C allows maintaining a high content of the spinel phase. In the structure of materials obtained by sintering powders with initially high spinel content at 1300 °C, grains of abnormally large size are formed. This leads to an increase in the initial permeability, magnetic induction at Hm = 1200 A/m, f = 10 kHz and magnetic losses at high frequencies (up to 500 kHz). A material with fine-grained structure was obtained by using air at the heating stage of pressureless sintering. This contributed to the reduction of magnetic losses without a significant decrease in Bm.","PeriodicalId":9964,"journal":{"name":"Chimica Techno Acta","volume":"65 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135460690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0