Superconducting Properties and Structural Features of Solid Solutions on the Base of Barium-Samarium Cuprate

2009 ◽  
Vol 4 (1) ◽  
pp. 68-74
Author(s):  
Aleksandr Blinov ◽  
Margarita Kameneva ◽  
Ludmila Kozeeva

Superconducting properties, structural and microstructural features of single-phase polycrystalline samples of bariumsamarium cuprate and solid solution on the base of Sm1+xBa2–xCu3O6+y (123SmSS) with х = 0.0–0.7 prepared in air were studied. It was shown that the solid solution decomposes at 0.12 < х < 0.3 by the spinodal mechanism to form layered microstructures with a variable Sm/Ba ratio. The data obtained are useful for understanding the mechanisms of the formation of possible vortex pinning centers in Ln1+xBa2–xCu3O6+у phases with «light» Ln.

1980 ◽  
Vol 43 (331) ◽  
pp. 851-856 ◽  
Author(s):  
Kosuke Onuma ◽  
Masahide Akasaka

SummaryUnusual clinopyroxenes were synthesized in the study of the join CaFeAlSiO6-CaTiAl2O6 in air at I atm. Clinopyroxene solid solution, hibonite solid solution, X-phase, perovskite, and corundum are present, and at subsolidus temperatures the clinopyroxene singlephase field extends up to about 19 wt% CaTiAl2O6. The CaTiAl2O6 component in the clinopyroxene however increases beyond the clinopyroxene single-phase field and attains 23 wt%. These clinopyroxene solid solutions are extremely poor in SiO2 and extremely rich in Al2O3, Fe2O3, and TiO2, and more than half of tetrahedral sites are occupied by AlIV, contravening the aluminium avoidance principle.


2021 ◽  
Vol 8 (1) ◽  
pp. 20218108
Author(s):  
A. V. Bryuzgina ◽  
A. S. Urusova ◽  
I. L. Ivanov ◽  
V. A. Cherepanov

YFe1-xСоxO3 solid solutions were prepared by glycerol-nitrate technique. The homogeneity range of solid solutions was studied within the temperature range 1173 – 1573 K. A continues series of solid solution below the decomposition temperature of YСоO3, which was shown to be equal to 1266 ± 6 K, begins to narrow at higher temperatures and becomes equal to 0 ≤ x ≤ 0.1 at 1573 K. The phase diagram of the YFeO3 – YСoO3 system in the “T – composition” coordinates was divided into three fields. Similar to the parent ternary oxides, all single-phase YFe1-xСоxO3 solid solutions possess orthorhombically distorted perovskite structure (Pnma space group). Unusual behavior of orthorhombic distortions in YFe1-xСоxO3 with temperature was explained by probable changes in spin state of Co3+ ions.


2010 ◽  
Vol 97-101 ◽  
pp. 182-186
Author(s):  
Yu Ping Tong ◽  
Jing Wang ◽  
Rui Zhu Zhang ◽  
Shun Bo Zhao

Well-dispersed Nd1.6Eu0.4Zr2O7 solid solutions were successfully prepared by a convenient salt-assisted combustion process using glycine as fuel. The samples were characterized by XRD, Raman, TEM and HRTEM. The results showed that the Nd ion can be partially replaced by Eu ion. The substituted product was still single-phase solid solutions and the crystal form remained unchanged. TEM images showed that the Nd1.6Eu0.4Zr2O7 solid solutions were composed of well-dispersed sphere-shaped nanocrystals with an average size of 30 nm, which is consistent with the value obtained from XRD patterns using the Scherrer formula. Moreover, the fluorescent characterization of the Nd1.6Eu0.4Zr2O7 nanocrystals at 385 nm upon excitation was carried out at room temperature, and the results showed that there were some intense and prevailing emission peaks located at 590-650 nm.


2015 ◽  
Vol 230 ◽  
pp. 62-66 ◽  
Author(s):  
Konstantin L. Bychkov ◽  
Katerina V. Terebilenko ◽  
Rostyslav P. Linnik ◽  
Nikolay S. Slobodyanik

Solid solution BiP0.9V0.1O4 from BiPXV1-XO4 system has been synthesized by solid state synthesis at 973 K. It has been shown that the phosphate-vanadate can be prepared as a single phase for x =0.9, while higher degree of (P/V)O4 substitution in BiVO4 has not been detected for the range studied. The substitution peculiarities have been investigated by X-Ray powder diffraction, infrared and photoluminescence spectroscopy. The luminescence spectrum of BiPXV1-XO4:Eu3+ solid solution reveal intensive photoluminescence lines related to f-f electronic transitions in Eu3+ ions.


2020 ◽  
Vol 8 (45) ◽  
pp. 16168-16179
Author(s):  
Quentin Micard ◽  
Anna L. Pellegrino ◽  
Raffaella Lo Nigro ◽  
Ausrine Bartasyte ◽  
Guglielmo G. Condorelli ◽  
...  

Accurate control of the MOCVD process parameters results selectively and reproducibly in the formation of two different systems: a single-phase solid solution film and a nanocomposite sample formed by nanocolumns embedded in a solid solution film.


2004 ◽  
Vol 821 ◽  
Author(s):  
S. Swaminathan ◽  
S. Chandrasekar ◽  
W. D. Compton ◽  
K. P. Trumble ◽  
A. H. King

AbstractA study has been made of the effect of solute (Mn, Al, Ni) additions on microstructure refinement due to large strain deformation in single phase, copper solid solutions. The solutes were specifically selected for their influence on stacking fault energy (SFE) of copper, and the large strain deformation was imposed by chip formation in machining. The microstructure of Cu- 0.7at%Ni chip consists of elongated, sub-micrometer sized grains while Cu-7at%Al chip is made up of long, thin microbands with twins. The microstructure of the chip changes as the SFE of the material varies. With all of the solid solutions studied, the hardness of the chips is found to be significantly greater than that of the bulk material. Recrystallization temperature of solid solution chips is found to be higher than those of pure copper chips.


2009 ◽  
Vol 23 (17) ◽  
pp. 3465-3469 ◽  
Author(s):  
GERMÁN SERRANO ◽  
ADRIANA SERQUIS ◽  
LEONARDO CIVALE ◽  
BORIS MAIOROV ◽  
TERRY G. HOLESINGER ◽  
...  

In this work we describe the effects of adding different amount of single-wall (sw) carbon nanotubes (CNT) on the superconducting properties of MgB 2. We observed that the amount of swCNT that partially dilute into the MgB 2 matrix is lower than for double-wall (dw) CNT samples for the same nominal content. This C incorporation leads to an increase of the upper critical field (Hc2), with a maximum Hc2(0) extrapolated value of 33.5 T, expected for a two-gap superconductor in the dirty limit. At the same time, the fraction of swCNT that has not been incorporated into MgB 2 lattice may retain their structural integrity acting as strong vortex pinning centers. In this case the optimum nominal swCNT content for increasing critical current density (Jc) is in the range 7.5-10%at.


2019 ◽  
Vol 37 (3) ◽  
pp. 1003-1022 ◽  
Author(s):  
Amitava Choudhury ◽  
Tanmay Konnur ◽  
P.P. Chattopadhyay ◽  
Snehanshu Pal

Purpose The purpose of this paper, is to predict the various phases and crystal structure from multi-component alloys. Nowadays, the concept and strategies of the development of multi-principal element alloys (MPEAs) significantly increase the count of the potential candidate of alloy systems, which demand proper screening of large number of alloy systems based on the nature of their phase and structure. Experimentally obtained data linking elemental properties and their resulting phases for MPEAs is profused; hence, there is a strong scope for categorization/classification of MPEAs based on structural features of the resultant phase along with distinctive connections between elemental properties and phases. Design/methodology/approach In this paper, several machine-learning algorithms have been used to recognize the underlying data pattern using data sets to design MPEAs and classify them based on structural features of their resultant phase such as single-phase solid solution, amorphous and intermetallic compounds. Further classification of MPEAs having single-phase solid solution is performed based on crystal structure using an ensemble-based machine-learning algorithm known as random-forest algorithm. Findings The model developed by implementing random-forest algorithm has resulted in an accuracy of 91 per cent for phase prediction and 93 per cent for crystal structure prediction for single-phase solid solution class of MPEAs. Five input parameters are used in the prediction model namely, valence electron concentration, difference in the pauling negativeness, atomic size difference, mixing enthalpy and mixing entropy. It has been found that the valence electron concentration is the most important feature with respect to prediction of phases. To avoid overfitting problem, fivefold cross-validation has been performed. To understand the comparative performance, different algorithms such as K-nearest Neighbor, support vector machine, logistic regression, naïve-based approach, decision tree and neural network have been used in the data set. Originality/value In this paper, the authors described the phase selection and crystal structure prediction mechanism in MPEA data set and have achieved better accuracy using machine learning.


2011 ◽  
Vol 3 (Special Issue) ◽  
pp. 1-7
Author(s):  
A. M. Dymshits ◽  
A. V. Bobrov ◽  
L. Bindi ◽  
K. D. Litasov ◽  
A. F. Shatskiy ◽  
...  

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