-
Details
-
Hits: 16
The effectiveness of using borate (borax) and fluoride (sodium fluoride) fluxes in the sintering of crystalline (sand) and amorphous (diatomite) silicate raw materials was considered. The change in the density and appearance of samples
with varying degrees of fluxes during their heat treatment at different temperatures was described. It was shown that
the introduction of 4 wt. % borax reduces the temperature to reach a density of 1500 kg/m3 by 100 °C, and 6 wt. % borax – by 200 °C. It was shown that the introduction of fluxes increases the amount of X-ray amorphous glass phase due
to depolymerization of the silicon-oxygen network and the formation of a low-temperature melt.
-
Details
-
Hits: 15
An overview of dielectric materials with high (more than 10 000) values of relative permittivity is presented. Most of the compositions of these materials are based on systems that include ferroelectric and non-ferroelectric components,
as well as solid solutions based on them. Various approaches to increasing the dielectric permittivity of materials are considered: doping, sintering atmosphere, grinding time, sintering temperature, grain size. The effect of dopants and the synthesis method on the value of characteristics of capacitor ceramics that can be used in the low-frequency and high-frequency range is compared.
-
Details
-
Hits: 18
The glass of 12.5Li2O–50GeO2–37.5P2O5 composition was synthesized by melt quenching. By means of its thermal annealing, single-phase LiGe2(PO4)3 composition was obtained, which is promising as a solid electrolyte for all-solid-state lithium-ion power sources. Using total X-ray scattering with analysis of the pair distribution function, and diffuse reflectance spectroscopy in the UV-Vis range, the local structure and optical properties of initial (amorphous) glass and crystallized glass were studied. An assessment of the influence of the effect of glass crystallization on these properties was carried out. It has been shown that structuration in the glass is observed only at the level of the first-second coordination sphere of Ge and P atoms. From the optical absorption spectra of the initial glass, the presence of F+ centers in the glass has been revealed, and their concentration decreases as a result of glass crystallization. The estimated value of the band gap for the crystallized glass, i.e. for the LiGe2(PO4)3 phase, is 6.15 eV for the case of direct allowed transitions, which exceeds the calculated value known from the literature by approximately 2 times.
-
Details
-
Hits: 20
Within the scope of the study, glasses co-doped with Sm3+/Gd3+ in the B2O3–GeO2–Bi2O3 system were synthesized,
covering compositions of 40B2O3–40GeO2–(15…17)Bi2O3–(3…2)Sm2O3–(2…1)Gd2O3 and 42,5B2O3–42,5GeO2–(11,25…12,75)Bi2O3–(2,25…1,50)Sm2O3–(1,500…0,075)Gd2O3. An assessment of luminescent characteristics was
conducted within the temperature range of 298 to 673 K. Spectral bands of photoluminescence associated with transitions between various Stark sublevels of Sm3+ ions were identified. Redistribution of the fluorescence intensity ratio corresponding to transitions 4G5/2 ? 6H9/2 ( = 645 nm) and 4G5/2 ? 6H7/2 ( = 597 nm) was observed. Based on the obtained
data, calculations of the fluorescence intensity ratio FIR, as well as relative sensitivity SR, were performed. The obtained results indicate the promising potential of these glasses as luminescent thermometric materials.
-
Details
-
Hits: 18
The features of glass batch preparation in the production colorless sheet glass with increased transparency are considered. A non-standard algorithm for dosing and loading selenium, cobalt oxide, erbium oxide and iron oxide into the mixer
was proposed.
-
Details
-
Hits: 14
A method for measuring the resistive characteristics of channels in the blanks of microchannel plates has been developed. Two probes are used for measurements, which minimizes leakage currents through adjacent channels.
The resistive properties of single channels of the microchannel insert of the restored blank of the microchannel plate MKP 18-10 have been studied. It is established that the resistance of the channels depends on their position in the microchannel honeycomb. It is shown that the channels located in close proximity to the monolithic frame have less resistance compared to those located in the middle of a stranded glass honeycomb.
-
Details
-
Hits: 21
It was found that it is possible to obtain high-strength ceramic paving stones based on loess rocks with the addition of 20 % glass waste powder. At the same time, the amount of moisture in the ation should be close to 10 %, which corresponds
to the semi-dry pressing technoloformgy.
-
Details
-
Hits: 23
The publication presents general information about calcium zirconate and the physical/chemical characteristics of products based thereon. The main fields of application of ceramic and refractory materials based on CaZrO3 are also considered.
-
Details
-
Hits: 33
In the present study, we presented a review progress in sol-gel method for the synthesis of powders of ferroelectric ceramics of the PbTiO3–PbZrO3 system, based on the controlled hydrolysis of mixtures of salts or organometallic compounds of lead, zirconium, and titanium. To obtaining materials of the PbTiO3–PbZrO3 system, the main attention is paid to the sol-gel conditions, the heat treatment conditions, the raw materials, the obtaining the precursor conditions, the gels drying, and the PbTiO3–PbZrO3 powder crystallization.
-
Details
-
Hits: 33
Using glass as a structural element that could obtain the role of the primary load-bearing elements of iconoclast structures has had a superficial history. Because of its aesthetic and admissible mechanical properties, glass has been considered one of the structural elements in the construction industry. Because of its extra safety, laminated glass on top of the most widely used elements has been appraised with more depth. The study aimed to evaluate the failure modes in laminated glass and the possibility of detecting the pre-failure status of the surveyed elements, referring to the proffered approaches and image processing (IP) procedures in the literature. The outcomes have compared the peculiarity and strength points of various routes and have reached the inference for proper approaches in every procedure. According to the results, image processing (IP) is the most appropriate method of pre-failure detection in load-bearing laminated glass elements. Among the image processing (IP) techniques, digital image correlation has the widest application. The results of this study, in combination with other pieces of research, may propound a database for evaluating the failure status of glass structures.
