scholarly journals Effect of size factor on the Ruddlesden-Popper single-slab compounds structure features

2019 ◽  
Vol 7 (1) ◽  
pp. 10-15 ◽  
Author(s):  
Yuriy A. Titova ◽  
Nadegda N. Belyavina ◽  
Mikola S. Slobodyanik ◽  
Olesya I. Nakonechna ◽  
Nataliia Y. Strutynska
Keyword(s):  
Rare Earth ◽  
Maximum Degree ◽  
Alkaline Earth ◽  
Rietveld Method ◽  
Rare Earth Metals ◽  
Size Factor ◽  
Structure Changes ◽  
Mutual Inclination

Character of influence of the strontium atoms replacement by smaller atoms of calcium on structure features of the Ruddlesden-Popper (Sr,Ca)LaScO4 (A2BO4) single-slab compoundis established. Structure of phase with a maximum degree of replacementhas determined by the Rietveld method. It is shown that such type of substitution increases a degree of AO9 interblock polyhedra deformation, mutual inclination of the BO6 octahedra and a decrease of A - О interblock bond. Presence of structure changes is the precondition for regulation of structural-dependent features of the materials on the base of scandates alkaline-earth and rare earth metals.

scholarly journals Effect of strontium atoms substitution on the features of two-slab structure of Sr1-xCaxLa2Sc2O7 scandates

2021 ◽  
Vol 9 (1) ◽  
pp. 44-50
Author(s):  
Yuri Titov ◽  
Nadezhda Belyavina ◽  
Mykola Slobodyanik ◽  
Olesya Nakonechna ◽  
Nataliia Strutynska
Keyword(s):  
Bond Length ◽  
Maximum Degree ◽  
Alkaline Earth ◽  
Rietveld Method ◽  
Rare Earth Metals ◽  
Three Dimensional ◽  
Structural Features ◽  
Dimensional Structure ◽  
Structure Changes ◽  
Group A

Effects of substitution of the Strontium atoms with smaller Calcium atoms on the structural features of the Ruddlesden-Popper SrLa2Sc2O7 two-slab compound is established. The crystal structure of orthorhombic Sr0.85Ca0.15La2Sc2O7 phase with maximum degree of substitution was determined by the Rietveld method (Fmmm space group, a = 0.5766(2) nm, b = 0.5743(2) nm, c = 2.0522(7) nm). Comparison of the structural features of SrLa2Sc2O7 and Sr0.85Ca0.15La2Sc2O7 shows that such type of substitution leads to a decrease in the (La,Sr)2 - О2 interblock bond length (from 0.222 (2) nm at x = 0 to 0.215 (1) nm at x = 0.15). The decrease in interblock bond length brings the constitution of the two-dimensional structure Sr1-хCaxLa2Sc2O7 closer to the structure of the three-dimensional perovskite, leads to its instability at х > 0.15 and gives a reason to conclude that this factor causes a limitation of region of the Sr1-хCaxLa2Sc2O7 solid solutions with a slab perovskite-like structure. Presence of such structure changes is the precondition for regulation of structural-dependent features of the materials on the base of scandates alkaline-earth and rare earth metals.

Phase composition of modern microcrystalline modifiers containing silicon, alkaline earth and rare earth metals

2020 ◽  
pp. 25-34
Author(s):  
V. P. Ermakova ◽  
◽  
S. Yu. Melchakov ◽  
V. G. Smirnova ◽  
L. A. Ovchinnikova ◽  
...  
Keyword(s):  
Rare Earth ◽  
Phase Composition ◽  
Alkaline Earth ◽  
Rare Earth Metals

scholarly journals The Structural and Phase State of the TiAl System Alloyed with Rare-Earth Metals of the Controlled Composition Synthesized by the “Hydride Technology”

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 859 ◽  
Author(s):  
Akbayan Belgibayeva ◽  
Yuri Abzaev ◽  
Natalia Karakchieva ◽  
Rakhmetulla Erkasov ◽  
Victor Sachkov ◽  
...  
Keyword(s):  
Rare Earth ◽  
Phase State ◽  
Rietveld Method ◽  
Rare Earth Metals ◽  
Quantitative Phase Analysis ◽  
X Ray ◽  
Alloying Additions ◽  
Transmission Electron ◽  
Local Areas ◽  
Full Profile

The structural state and the quantitative phase analysis of the TiAl system, alloyed with rare-earth metals synthesized using hydride technology, were studied in this work. Using the Rietveld method, the content of the major phases in the initial system Ti(50 at.%)–Al(50 at.%), as well as Ti(49 at.%)–Al(49 at.%), with alloying additions Ta, Y and Dy having a high accuracy was determined. The methods of scanning electron microscopy, transmission electron microscope and X-ray spectral microanalysis of the local areas of the structure for studying the distribution of alloying elements were used. The energies of lattices of separate phases were also determined after the full-profile specification. All the lattices of the identified structures (about 30) turned out to be stable. It was established that in the Ti(49 at.%)–Al(49 at.%) systems under study with alloying additions of metals Ta, Y and Dy, there were intermetallides composed of AlTi3, TiAl in the hexagonal, tetragonal and triclinic units. It is known that after microalloying alloys by Y and Dy metals, the mass fraction of TiAl phases increases significantly (>70%).

Magnetic susceptibility of liquid heavy rare earth metals

1979 ◽  
Vol 40 (C5) ◽  
pp. C5-260-C5-261 ◽  
Author(s):  
M. Müller ◽  
E. Huber ◽  
H.-J. Güntherodt
Keyword(s):  
Magnetic Susceptibility ◽  
Rare Earth ◽  
Rare Earth Metals ◽  
Heavy Rare Earth
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