International Journal of Self-Propagating High-Temperature Synthesis最新文献

{"title":"Influence of Nd3+ on Structural, Optical, Electrical, Dielectric, Magnetic, and NO2 Gas Sensing Properties of Nd3+ Substituted Ni–Cu Ferrites","authors":"S. M. Patil,&nbsp;S. S. Potdar,&nbsp;P. B. Belavi,&nbsp;B. K. Bammannavar,&nbsp;G. N. Chavan,&nbsp;S. A. Malladi,&nbsp;K. A. Thabaj,&nbsp;M. K. Rendale,&nbsp;L. R. Naik","doi":"10.3103/S1061386225700207","DOIUrl":"10.3103/S1061386225700207","url":null,"abstract":"<p>The Nd³⁺ substituted Ni–Cu ferrites having the general chemical composition of Ni_0.5Cu_0.5Nd_<i>x</i>Fe_2–<i>x</i>O₄ (<i>x</i> = 0.1, 0.2, and 0.3) were synthesized by solid state reaction method. The XRD analysis revealed the confirmation and formation of cubic spinel structure of ferrites. The lattice parameter value varied from 8.318 to 8.343 Å. The lattice parameter and X-ray density were found to increase with increasing Nd³⁺ ion concentration due to higher ionic radius of Nd³⁺ ion. The SEM images illustrated that crystallite size decreases with increasing Nd³⁺ ion concentration due to unit cell growth and lattice distortion, which produces an internal stress preventing grain growth. From the FTIR spectra, the higher frequency band in the range of 500–600 cm^–1 confirmed the vibrations due to M–O stretching at the tetrahedral site, while the lower band in the range of 400–500 cm^–1 confirmed the movement of Fe⁺³–O^2– band group at the octahedral site. The higher the concentration of Nd³⁺ ions, the higher the resistivity of Nd-doped ferrites due to change in crystal structure and electronic configuration. For all Nd³⁺ doped samples, the dielectric constant and dielectric loss decreased with increasing frequency, representing the typical dielectric dispersion behaviour, and the AC conductivity increased. The optical band gap of Nd³⁺ substituted compounds were studied using UV-Vis spectrum. The absorbance wavelength of ferrites reduced with the substitution, the indirect band gap energy increased. When Nd³⁺ ions replaced Fe³⁺ ions on the tetrahedral B-site, the saturation magnetization increased. The coercivity decreased due to an increase in grain size which happens owing to substitution of Nd³⁺ ion. Gas sensing properties of Nd³⁺ doped ferrites were studied by using NO₂ gas. Sensitivity of ferrites was enhanced by Nd³⁺ doping via increasing the number of oxygen vacancies which improves the absorption of NO₂ gas.</p>","PeriodicalId":595,"journal":{"name":"International Journal of Self-Propagating High-Temperature Synthesis","volume":"34 3","pages":"221 - 232"},"PeriodicalIF":0.6,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144905281","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}

{"title":"Solution Combustion Synthesis of ZnO Nanoparticles Using an Aqueous Extract of Laurel Leaves as a Natural Fuel","authors":"E. A. Chavarriaga,&nbsp;A. Gómez,&nbsp;Y. Cardona Maya,&nbsp;W. D. Cardona Maya,&nbsp;A. A. Lopera","doi":"10.3103/S1061386225700219","DOIUrl":"10.3103/S1061386225700219","url":null,"abstract":"","PeriodicalId":595,"journal":{"name":"International Journal of Self-Propagating High-Temperature Synthesis","volume":"34 3","pages":"233 - 236"},"PeriodicalIF":0.6,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144905282","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}

{"title":"Preparation and Study of TiB2- and TiCB-supported Catalysts with Ni, NiCo, and CoCu Active Phases","authors":"E. V. Pugacheva,&nbsp;I. M. Bystrova,&nbsp;R. A. Kochetkov,&nbsp;N. I. Abzalov,&nbsp;B. S. Seplyarskii,&nbsp;V. N. Borshch","doi":"10.3103/S1061386225700141","DOIUrl":"10.3103/S1061386225700141","url":null,"abstract":"<p>NiAl, NiCoAl, and CoCuAl intermetallics on ceramic TiB₂ and TiCB supports were produced through SHS of granular mixtures and used as precursors for preparation of catalysts for CO and propane deep oxidation and CO₂ hydrogenation. The precursors were converted into catalysts by leaching with 20% NaOH solution and stabilization with 10% H₂O₂ solution. The activity and selectivity of catalysts was found to be determined by active phase composition. In CO₂ methanation, NiCo/TiB₂ catalyst gave the highest CO₂ conversion (69.5% at 350°C) with 100% methane selectivity. In addition, NiCo/TiB₂ was shown to the most active in propane oxidation (15.7% conversion at 450°C). 100% CO conversion was observed on catalysts with CoCu active phase at 400°C.</p>","PeriodicalId":595,"journal":{"name":"International Journal of Self-Propagating High-Temperature Synthesis","volume":"34 3","pages":"161 - 171"},"PeriodicalIF":0.6,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144905260","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}

{"title":"Hydride Cycle Synthesis of Ti0.5V2Cr0.5 Alloy and Its Composites with ZrNi/Zr7Ni10 Additives by a Novel Technological Approach","authors":"A. Aleksanyan,&nbsp;N. Sisakyan,&nbsp;D. Mayilyan","doi":"10.3103/S1061386225700177","DOIUrl":"10.3103/S1061386225700177","url":null,"abstract":"<p>This study presents, for the first time, the mechanisms governing the formation of the ternary Ti_0.5V₂Cr_0.5 base alloy and its composite alloys (incorporating 4 wt % ZrNi and 4 wt % Zr₇Ni₁₀ activating additives), synthesized via hydride cycle (HC) method. Additionally, the interaction of these alloys with hydrogen was systematically investigated. The synthesis was conducted through two distinct technological routes, each resulting in different formation mechanisms of the final composite materials. XRD analysis confirmed that all synthesized alloys form solid solutions with BCC crystal structure, exhibiting nearly identical lattice parameters. The hydrogen interaction of the synthesized alloys was examined under self-propagating high-temperature synthesis (SHS) and short-term activation method (STAM, 15–30 min). In both cases, the hydrides of FCC structure with hydrogen storage capacities ranging from 2.46 to 3.06 wt % were formed. The desorption temperatures of the synthesized hydrides differ due to the different microstructures of the alloys. Hydrides synthesized via STAM using composites obtained through the first synthesis route exhibited a hydrogen capacity of 3.01 wt % and a lower decomposition temperature characterized by a single endothermic peak at 280°C on the differential thermal analysis (DTA) curve. These findings demonstrate the potential of using Ti_0.5V₂Cr_0.5-based alloys for hydrogen storage applications.</p>","PeriodicalId":595,"journal":{"name":"International Journal of Self-Propagating High-Temperature Synthesis","volume":"34 3","pages":"192 - 208"},"PeriodicalIF":0.6,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144905274","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}

{"title":"Obtaining New Porous Materials by Self-Propagating High-Temperature Synthesis and Using Them as Neutralizing Catalysts in Vehicles","authors":"A. I. Khvadagiani,&nbsp;M. E. Iremadze,&nbsp;R. M. Topuria,&nbsp;D. G. Zalkaliani,&nbsp;R. M. Pilia","doi":"10.3103/S106138622570013X","DOIUrl":"10.3103/S106138622570013X","url":null,"abstract":"<p>At present, vehicle exhausts are among the major factors of environmental pollution. This problem is particularly acute in developing countries, where the share of used cars is high because the catalytic converters in used cars are partially or often completely out of order, which leads to the increase of toxic substances in the air such as carbon monoxide, nitric oxides, and hydrocarbons. We used the SHS method to obtain a new type of catalytic substrate, in which precious metals (platinum, palladium, rhodium) can be partially or completely replaced with metals such as copper, nickel, chromium, etc. When obtaining the catalytic substrate by the SHS method, the correct selection of a chemical composition of the initial charging material of the reaction is a determining factor that ultimately leads to obtaining products with the desired properties. Due to the high degree of dispersion of additive metals (copper, chromium, nickel, etc.), they do not participate in the reaction, therefore, they do not form chemical compounds, and they are evenly distributed in the final product, which significantly increases the quality of their catalytic activity. The porosity of the obtained sample is significantly affected by the density of the initial sample. By changing the initial porosity of the sample, it is possible to vary the porosity of the final product from 5 to 45%. Application of the proposed technology reduces the neutralizer-catalyst’s production cost and solves the problem of its scarcity. The obtained materials can be used in all types of vehicles with internal combustion engines, as well as in enterprises where catalytic purification of exhaust gases and liquids takes place.</p>","PeriodicalId":595,"journal":{"name":"International Journal of Self-Propagating High-Temperature Synthesis","volume":"34 3","pages":"156 - 160"},"PeriodicalIF":0.6,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144905262","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}

{"title":"High-Temperature Synthesis of V2AlC MAX Phase: Influence of Al","authors":"V. A. Gorshkov,&nbsp;P. A. Miloserdov,&nbsp;I. D. Kovalev","doi":"10.3103/S1061386225700189","DOIUrl":"10.3103/S1061386225700189","url":null,"abstract":"<p>Cast materials based on MAX V₂AlC phase were prepared by self-propagating high-temperature synthesis (SHS) under 5 MPa of Ar pressure from green mixtures containing V₂O₅, VO₂, Al, and C powders. Variation in an excess of aluminum markedly affected the process parameters and phase composition/microstucture of combustion products. The synthesized samples were shown to contain V₂AlC as a basis with additions of carbide and intermetallic phases of vanadium, whose presence is probably associated with a short lifetime of the liquid phase due to small green mixture mass and strong heat loss into the environment. A maximum content of MAX V₂AlC phase in the ingot (68 wt %) was reached at 15% of excess aluminum.</p>","PeriodicalId":595,"journal":{"name":"International Journal of Self-Propagating High-Temperature Synthesis","volume":"34 3","pages":"209 - 214"},"PeriodicalIF":0.6,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144905275","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}

{"title":"Influence of Impurity Gases on Combustion of Ti + 2B Mixture","authors":"Yu. V. Bogatov,&nbsp;V. A. Shcherbakov","doi":"10.3103/S1061386225700190","DOIUrl":"10.3103/S1061386225700190","url":null,"abstract":"<p>A comparative analysis of forced SHS compaction of single- and double-layer pressed Ti + 2B mixtures was carried out. High-velocity impurity gases were found to be able to initiate SHS reaction in the green mixture. It was shown that the use of double-layer combustion scheme permits to reduce the burning time of pellet in half due to the propagation of red-hot impurity gases between its layers. Their propagation velocity was found to be determined by total pellet mass: the larger the pellet mass, the higher the propagation velocity of impurity gases through artificially organized channels (gaps between the layers). Short burning time reduces the delay interval for the onset of consolidation of SHS products and facilitates the consolidation of synthesis products (hot pressing) at higher temperature and lower temperature gradient over the burned pellet.</p>","PeriodicalId":595,"journal":{"name":"International Journal of Self-Propagating High-Temperature Synthesis","volume":"34 3","pages":"215 - 220"},"PeriodicalIF":0.6,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144905280","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}

{"title":"Features of Combustion Wave Propagation in Ni–Al/quartz glass/Ni–Al System","authors":"V. G. Prokof’ev","doi":"10.3103/S1061386225700128","DOIUrl":"10.3103/S1061386225700128","url":null,"abstract":"<p>Regularities of passage of gasless combustion wave through a quartz glass layer separating two cylindrical Ni–Al samples were considered. The time of passage of combustion wave through the quartz glass layer was calculated as a function of layer thickness and initial temperature. The unsteady dynamics and critical conditions of transient combustion process for Ni–Al system were investigated. The mathematical model and calculation results can be used to estimate the critical thickness of quartz glass layer separating SHS-produced samples.</p>","PeriodicalId":595,"journal":{"name":"International Journal of Self-Propagating High-Temperature Synthesis","volume":"34 3","pages":"151 - 155"},"PeriodicalIF":0.6,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144905261","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}

{"title":"Influence of Fuel Composition in Solution Combustion Synthesis on the Structure and Thermoelectric Properties of La-Doped SrTiO3","authors":"E. Chernyshova,&nbsp;S. Yudin,&nbsp;K. Podbolotov,&nbsp;K. Kuskov,&nbsp;D. Moskovskikh,&nbsp;V. Khovaylo","doi":"10.3103/S1061386225700165","DOIUrl":"10.3103/S1061386225700165","url":null,"abstract":"<p>High-temperature thermoelectric SrTiO₃ powders, including La-doped (Sr_0.95La_0.05)TiO₃, were synthesized using solution combustion synthesis. It was found that using urea as the organic fuel leads to the formation of a polyphase material consisting of 80 wt % SrTiO₃ and 20 wt % TiO₂ along with Sr₂TiO₄. The introduction of a fuel mixture of urea and glycine into the reaction solution significantly improved homogeneity of the powder, increasing the proportion of the target phase to 95 wt %. Spark plasma sintering further homogenized the powder, reducing amount of the impurity phase TiO₂ to less than 5 wt %. The study demonstrated that doping, phase composition, and porosity have a significant impact on the thermoelectric properties of SrTiO₃. The presence of TiO₂ secondary phase and porosity was shown to regulate the material’s electrical and thermal conductivities. La doping affected the charge carrier concentration, and together with the other factors, enabled the production of a dense (Sr_0.95La_0.05)TiO₃ sample with a figure of merit <i>ZT</i> ≈ 0.23 at 950 K. The findings underscore the significance of controlling phase composition, doping, and defect structure to enhance the thermoelectric performance of SrTiO₃, paving the way for the design of energy-efficient materials applicable in thermal energy conversion technologies.</p>","PeriodicalId":595,"journal":{"name":"International Journal of Self-Propagating High-Temperature Synthesis","volume":"34 3","pages":"180 - 191"},"PeriodicalIF":0.6,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144905273","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}

{"title":"Preparation of NiCo by Solution Combustion Synthesis Method","authors":"N. Amirkhanyan,&nbsp;M. Zakaryan","doi":"10.3103/S1061386225700153","DOIUrl":"10.3103/S1061386225700153","url":null,"abstract":"<p>In this study, NiCo composite materials were synthesized via the solution combustion synthesis (SCS) method using nickel and cobalt nitrates with hexamethylenetetramine as fuel. Thermodynamic calculations were first conducted to identify optimal fuel-to-oxidizer ratios (φ) and water content, revealing that the maximum adiabatic temperature (2670 K) occurs at φ = 1.25. Experimental results showed that combustion could not be initiated at φ = 0.5, while φ = 1.5 yielded the highest combustion temperature (1580 K) and a pure NiCo composite phase, as confirmed by XRD analysis. The synthesized materials exhibited a porous sintered microstructure with an average crystallite size of ~25 nm. Pressure variation from 0.1 to 1.5 MPa had negligible influence on the phase composition but significantly affected combustion wave velocity, which increased by two orders of magnitude. SEM analysis confirmed that all samples retain porous and sintered morphology, with higher pressures leading to more pronounced sintering. These results demonstrate that the SCS method enables the rapid and effective synthesis of structurally uniform NiCo composites with tunable properties.</p>","PeriodicalId":595,"journal":{"name":"International Journal of Self-Propagating High-Temperature Synthesis","volume":"34 3","pages":"172 - 179"},"PeriodicalIF":0.6,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144905272","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}