Structure and crystallization of SiO2and B2O3doped lithium disilicate glasses from theory and experiment

2017 ◽  
Vol 19 (37) ◽  
pp. 25298-25308
Author(s):  
Andreas Erlebach ◽  
Katrin Thieme ◽  
Marek Sierka ◽  
Christian Rüssel

Solid solutions of SiO2and B2O3in Li2O·2SiO2are synthesized and characterized for the first time by calculations and experiments.

2019 ◽  
Vol 7 (7) ◽  
pp. 2085-2095
Author(s):  
Gennady V. Bazuev ◽  
Alexander P. Tyutyunnik ◽  
Alexander V. Korolev ◽  
Emmanuelle Suard ◽  
Cheuk-Wai Tai ◽  
...  

Two ranges of mixed-valence manganese (Mn3+/Mn4+) SrMn1−xSbxO3 solid solution and corresponding magnetic structures were described for the first time.


2020 ◽  
Vol 22 (44) ◽  
pp. 25876-25891
Author(s):  
E. O. Gomes ◽  
L. Gracia ◽  
A. A. G. Santiago ◽  
R. L. Tranquilin ◽  
F. V. Motta ◽  
...  

In this work PbMoO4 and Pb1−2xCaxSrxMoO4 (x = 0.1, 0.2, 0.3, 0.4 and 0.5) solid solutions have been successfully prepared, for the first time, by a simple co-precipitation method and the as-synthesized samples were subjected to a water-based reflux treatment.


1998 ◽  
Vol 120 (4) ◽  
pp. 529-533 ◽  
Author(s):  
Dong Sun ◽  
James K. Mills

It is verified in theory and experiment that through proper design of the control gains, the simple PD position feedback can control a flexible sheet manipulated by two industrial robots to a desired position while regulating its deformations at the contacts to zero. The offsets of all static deformations of the sheet with reference to the original positions decay to zero. A hybrid controller is further developed to control the motion of the sheet as well as its interactions with the manipulators by adding a force feedforward term to the PD scheme. This is the first time that conventional PD control has been shown to be applicable for use in the manipulation of flexible payload.


2010 ◽  
Vol 67 ◽  
pp. 59-63 ◽  
Author(s):  
Oleg Ivanov ◽  
Elena Danshina ◽  
Yulia Tuchina ◽  
Viacheslav Sirota

Ceramic solid solutions of (1-x)SrTiO3-(x)BiScO3 system with x=0, 0.05, 0.1, 0.2, 0.3, 0.4 and 0.5 have been for the first time synthesized via solid-state processing techniques. Both of end compounds in this system are not ferroelectric materials. X-ray diffraction analysis revealed that at room temperature the samples under study at x=0.2, 0.3, 0.4 and 0.5 consist of mixture of center-symmetric cubic Pm3m phase and polar tetragonal P4mm phase. Anomalous behaviour of dielectric permittivity and dielectric losses for these samples is found to be specific one for ferroelectrics with diffuse phase transitions. Furthermore, examination of the polarization hysteresis behavior revealed weakly nonlinear hysteresis loops in the ferroelectric phase.


2020 ◽  
Vol 62 (6) ◽  
pp. 55-64
Author(s):  
Vyacheslav F. Markov ◽  
◽  
Karina V. Grashchenkova ◽  
Larisa N. Maskaeva ◽  
Yury G. Shashmurin ◽  
...  

In this work, we have attempted to detect the photoadsorption effect using various photoactivation sources of semiconductor layers of CdxPb1–xS solid solutions that are sensitive to the presence of nitrogen dioxide in air. For this purpose, CdxPb1–xS films (up to 600 nm thick) were synthesized from the citrate – ammonia reaction system by the chemical bath deposition (CBD) on glass and sitall substrates. Using XRD analysis, we determined the structure and composition of CdxPb1–xS solid solutions. It was found that all films crystallize in the cubic structure B1 of lead sulfide. Taking into account the content of the substituting component in the samples and comparing it with the equilibrium phase diagrams of the PbS-CdS system, we concluded that the obtained solid solutions are strongly supersaturated in nature. The cadmium content in the PbS lattice increases in films deposited on sitall and glass from 3.9 to 5.9 and from 4.3 to 5.4 at.% with an increase in the deposition time from 60 to 120 minutes, respectively. It must be noted that their crystallinity degree increases with increasing deposition time. The size of the particles forming the layers was determined by SEM microscopy. The predominant crystallite diameter is 250-300 nm. The sensory properties of films of CdxPb1–xS solid solutions with respect to the presence of nitrogen dioxide with a concentration of 100 mg/m3 in air were studied using preliminary photoactivation by various sources with a radiation wavelength from 420 to 1000 nm. For the first time, a positive photoadsorption effect was revealed for CBD produced films of CdxPb1–xS solid solutions. The preliminary photoactivation of the films with a blue lamp (760–1000 nm) for 9-13 minutes allows the film to increase the response to NO2 more than doubled. A high relaxation rate of CdxPb1–xS -based sensor elements after contact with nitrogen dioxide was shown to be 4–10 minutes, which allows to reuse it.


Author(s):  
Kirill V. Poletkin

This work presents the results of the experimental and theoretical study of the static pull-in of tilting actuation executed by a hybrid levitation micro-actuator (HLMA) based on the combination of inductive levitation and electrostatic actuation. A semi-analytical model to study such the pull-in phenomenon is developed, for the first time, as a result of using the qualitative technique based on the Lagrangian approach to analyze inductive contactless suspensions presented in work and a recent progress in the calculation of mutual inductance and force between two circular filaments. The obtained non-linear model, accounting for two degrees of freedom of the actuator, allows us to predict accurately the static pull-in displacement and voltage. The results of modelling were verified experimentally and agree well with measurements.


Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 286
Author(s):  
Iwona Lazar ◽  
Andrzej Majchrowski ◽  
Andrzej Soszyński ◽  
Krystian Roleder

Solid solutions of PbZr1−xTixO3 (PZT) are one of the most widely used piezoelectric materials with perovskite structure. Despite the decades of research, the phase diagram of PZT reported in 1971 has not been resolved yet. Recently, it turned out that single crystals of good quality of these solid solutions can be grown. By means of top-seeded solution growth (TSSG) technique, we succeeded to grow a single PbZr0.87Ti0.13O3 crystal. Hence, a partial verification of the diagram could be performed through investigations of the optical, dielectric, pyroelectric and elastic properties of this crystal, in a wide temperature range. The obtained results confirmed that the PbZr0.87Ti0.13O3 crystal undergoes a sequence of phase transitions, such as those observed in ceramics of similar chemical composition. However, additional anomalies of investigated physical properties were observed and discussed. Moreover, the influence of electric field on optical properties has been investigated for the first time and has proven the existence of local polar character of the phase above TC in a limited temperature range.


RSC Advances ◽  
2015 ◽  
Vol 5 (116) ◽  
pp. 96242-96252 ◽  
Author(s):  
H. Ait ahsaine ◽  
M. Ezahri ◽  
A. Benlhachemi ◽  
B. Bakiz ◽  
S. Villain ◽  
...  

This study on bismuth lutetium tungstates presents, for the first time, correlations between structure, vibrational and photoluminescence properties in the case of solid solutions Bi2−xLuxWO6. The origin of luminescence signals under UV excitation is discussed.


1996 ◽  
Vol 423 ◽  
Author(s):  
A. V. Dmitriev ◽  
A. L. Oruzheinikov

AbstractThe radiative recombination rates have been calculated for the first time in the wide band gap wurtzite semiconductors GaN, InN and AIN and their solid solutions GaxAl1−xN and InxAl1−xN on the base of existing data on the energy band structure and optical absorption in these materials. We calculated the interband matrix elements for the direct optical transitions between the conductivity band and the valence one using the experimental photon energy dependence of the absorption coefficient near the band edge. In our calculations we assumed that the material parameters of the solid solutions (the interband matrix element, carrier effective masses and so on) could be obtained by a linear interpolation between their values in the alloy components. The temperature dependence of the energy gap was taken in the form proposed by Varshni. The calculations of the radiative recombination rates were performed in the wide range of temperature and alloy compositions.


2021 ◽  
Vol 22 (14) ◽  
pp. 7700
Author(s):  
Susanne Jung ◽  
Marco Maria Moser ◽  
Johannes Kleinheinz ◽  
Arndt Happe

Gingivafibroblasts were cultured on lithium disilicate, on zirconia dioxide, and on titanium with two different surface roughnesses (0.2 µm and 0.07 µm); Proliferation (MTT), Living/Dead staining, cytotoxicity (LDH), proliferation (FGF2), and inflammation (TNFα) were analyzed after 1 day and 21 days. Furthermore, alteration in cell morphology (SEM) was analyzed. The statistical analysis was performed by a Kruskal–Wallis test. The level of significance was set at p < 0.05. There were no distinct differences in cellular behavior between the tested roughness. There were slight differences between tested materials. Cells grown on zirconia dioxide showed higher cytotoxic effects. Cells grown on lithium disilicate showed less expression of TNFα compared to those grown on zirconia dioxide or titanium. These effects persisted only during the first time span. The results indicate that the two tested high-strength ceramics and surface properties are biologically suitable for transmucosal implant components. The findings may help clinicians to choose the most appropriate biomaterial as well as the most appropriate surface treatment to use in accordance with specific clinical dental applications.


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