scholarly journals Phase equilibrium diagram of the Hf-Fe-Sn system at 1070 K

2021 ◽  
Vol 22 (4) ◽  
pp. 761-766
Author(s):  
L. Romaka ◽  
V.V. Romaka ◽  
Yu. Stadnyk ◽  
V. Pashkevych
Keyword(s):  
Phase Equilibrium ◽  
Annealing Temperature ◽  
Equilibrium Diagram ◽  
Experimental Studies ◽  
Structure Type ◽  
Binary Compound ◽  
Phase Equilibrium Diagram ◽  
Space Group ◽  
X Ray ◽  
Type Space

Experimental studies of the phase equilibrium diagram of the Hf-Fe-Sn ternary system at 1070 K were performed by X-ray powder diffractometry, scanning electron microscopy and electron probe microanalysis techniques in the whole concentration range. At annealing temperature four ternary compounds are realized: Hf6FeSn2 (K2UF6 structure type, space group P-62m), Hf1.8Fe5Sn3.8 (Hf1.82Fe5Sn3.82 structure type, space group Cmmm), Hf3Fe4Sn4 (Zr3Fe4Sn4 structure type, space group Pnma), and Hf9Fe3.7Sn10.3 (Hf9Fe4Sn10 structure type, space group Cmc21). An existence of the Hf1-xFe2+x-ySny solid solution formed by substitution of the iron atoms by tin in the Hf1-xFe2+x (MgZn2-type) binary compound up to 19 at. % Sn was found. Solubility of Fe in the Hf5Sn3 binary (Mn5Si3-type) extends up to 10 at. % (a=0.8363(2)-0.8324(4), c=0.5726(1)-0.5686(4) nm).

scholarly journals Interaction of the components in the Gd-Mn-Sn ternary system at 873 and 673 K

2018 ◽  
Vol 19 (1) ◽  
pp. 60-65
Author(s):  
L. P. Romaka ◽  
Yu. V. Stadnyk ◽  
V. V. Romaka ◽  
M. Konyk ◽  
R. Serkiz
Keyword(s):  
Solid Solution ◽  
Ternary System ◽  
Substitutional Solid Solution ◽  
Structure Type ◽  
Binary Compound ◽  
Interstitial Solid Solution ◽  
Space Group ◽  
X Ray ◽  
Type Space ◽  
Ternary Compounds

The interaction of the components in the Gd-Mn-Sn ternary system was studied using the methods of X-ray and microstructure analyses, in the whole concentration range. The phase diagrams of the Gd-Mn-Sn system were constructed at 873 and 673 K. At both temperature of investigation the Gd-Mn-Sn system is characterized by existence of two ternary compounds: GdMn6Sn6 (MgFe6Ge6 structure type, space group P6/mmm) and Gd4Mn4Sn7 (Zr4Co4Ge7 structure type, space group I4/mmm). The formation of the interstitial solid solution GdMnхSn2 based on GdSn2 (ZrSi2-type) binary compound was found up to 10 at. % Mn at 873 K and 673 K. The existence of the substitutional solid solution based on GdMn2 (MgCu2-type) was observed up to 5 at.% Sn and 3 at. % Sn at 873 K and 673 K, respectively.

Powder diffraction data of a new compound Al0.35GdGe2

2008 ◽  
Vol 23 (1) ◽  
pp. 60-62 ◽  
Author(s):  
Lingmin Zeng ◽  
Jiejun He ◽  
Pingli Qin ◽  
Xiangzhong Wei
Keyword(s):  
Ternary Compound ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Structure Type ◽  
Powder Diffraction Data ◽  
Space Group ◽  
X Ray ◽  
Type Space

A new ternary compound Al0.35GdGe2 has been synthesized and studied by means of X-ray powder diffraction technique. The ternary compound Al0.35GdGe2 crystallizes in the orthorhombicwith the CeNiSi2 structure type (space group Cmcm, a=4.0874(2) Å, b=16.1499(5) Å,c=3.9372(1) Å, Z=4, and Dcalc=8.007 g/cm3).

Compounds Ln5(Ag, Ga)19 – x (Ln = Gd, Tb) – Defective Partially Ordered Representatives of the Rb5Hg19 Structure Type

2005 ◽  
Vol 60 (9) ◽  
pp. 929-932 ◽  
Author(s):  
Roman V. Gumeniuk ◽  
Lev G. Akselrud ◽  
Yurij B. Kuz’ma
Keyword(s):  
Crystal Structures ◽  
Structure Type ◽  
Space Group ◽  
X Ray ◽  
Type Space ◽  
Partially Ordered ◽  
New Compounds

New compounds Ln5(Ag, Ga)19−x (Ln = Gd, Tb) have been found to crystallise with the Rb5Hg19 structure type (space group I4/m). The crystal structures were refined for Gd5Ag1.8Ga15 and Tb5Ag2Ga15.6 from X-ray powder data: a = 9.4635(1), c = 9.8638(2) Å , RI = 0.093 and a = 9.4313(1), c = 9.8491(2) Å , RI = 0.085, respectively. Some positions in the crystal structures of new the compounds are occupied partially.

scholarly journals Phase equilibria in the Gd–Cr–Ge system at 1070 K

2021 ◽  
Vol 22 (2) ◽  
pp. 248-254
Author(s):  
M. Konyk ◽  
L. Romaka ◽  
Yu. Stadnyk ◽  
V.V. Romaka ◽  
V. Pashkevych
Keyword(s):  
Phase Diagram ◽  
Isothermal Section ◽  
Ternary System ◽  
Electron Microprobe ◽  
Structure Type ◽  
Space Group ◽  
X Ray ◽  
Type Space ◽  
Ternary Compounds ◽  
Pearson Symbol

The isothermal section of the phase diagram of the Gd–Cr–Ge ternary system was constructed at 1070 K over the whole concentration range using X-ray diffractometry, metallography and electron microprobe (EPM) analysis. Three ternary compounds are realized in the Gd–Cr–Ge system at the temperature of annealing: Gd117Cr52Ge112 (Tb117Fe52Ge112 structure type,  space group Fm-3m, Pearson symbol cF1124, a = 2.8971(6) nm), GdCr6Ge6 (SmMn6Sn6 structure type, space group P6/mmm, Pearson symbol hP16, a = 0.51797(2), c = 0.82901(4) nm) and GdCr1-хGe2 (CeNiSi2 structure type, space group Cmcm, Pearson symbol oS16, a = 0.41569(1)-0.41593(8), b = 1.60895(6)-1.60738(3), c = 0.40318(1)-0.40305(8) nm). For the GdCr1-xGe2 compound the homogeneity range was determined (x=0.73 – 0,69).

scholarly journals Isothermal section of the Ho–Cu–Sn ternary system at 670 K

2019 ◽  
Vol 19 (2) ◽  
pp. 139-146
Author(s):  
L. Romaka ◽  
I. Romaniv ◽  
V. Romaka ◽  
M. Konyk ◽  
A. Horyn ◽  
...  
Keyword(s):  
Solid Solution ◽  
Isothermal Section ◽  
Ternary System ◽  
Binary Compound ◽  
X Ray Diffraction ◽  
Interstitial Solid Solution ◽  
Space Group ◽  
X Ray ◽  
Type Space ◽  
Ternary Compounds

The interaction of the components in the Ho-Cu-Sn ternary system was investigated at 670 K over the whole concentration range using X-ray diffraction and EPM analyses. Four ternary compounds were formed in the Ho–Cu–Sn system at 670 K: HoCuSn (LiGaGe type, space group P63mc), Ho3Cu4Sn4 (Gd3Cu4Ge4-type, space group Immm), HoCu5Sn (CeCu5Au-type, space group Pnma), and Ho1.9Cu9.2Sn2.8 (Dy1.9Cu9.2Sn2.8-type, space group P63/mmc). The formation of the interstitial solid solution based on HoSn2 (ZrSi2-type) binary compound up to 5 at. % Cu was found.

Fehlende Glieder bekannter Reihen: Die Oxoferrate(III) Rb8[Fe2O7], Rb6[Fe2O6] und K4[Fe2O5] / Missing Links in Known Series: The Oxoferrates(III) Rb8[Fe2O7], Rb6[Fe2O6], and K4[Fe2O5]

2005 ◽  
Vol 60 (7) ◽  
pp. 732-740 ◽  
Author(s):  
Gero Frisch ◽  
Caroline Röhr
Keyword(s):  
Single Crystal ◽  
Structure Type ◽  
Potassium Ferrate ◽  
X Ray Diffraction ◽  
Marked Contrast ◽  
Ionic Radii ◽  
Space Group ◽  
X Ray ◽  
Type Space ◽  
Alkaline Cations

The title compounds were synthesized at temperatures between 775 and 1175 K from (mostly stoichiometric) mixtures of Fe2O3, elemental rubidium or potassium (A) and their hyperoxides AO2. The structures have been determined by single crystal X-ray diffraction. The alkaline rich ferrate(III) Rb8[Fe2O7] (Cs8[Fe2O7] structure type, space group P21/c, a = 696.7, b = 1722.1, c = 692.0 pm, β = 119.40°, Z = 2, R1 = 0.0496) exhibits diferrate anions [Fe2O7]8- composed of two vertexsharing [FeIIIO4] tetrahedra with a linear Fe-O-Fe bridge and nearly ideal 3m symmetry. This is in marked contrast to the Na homologue, where the diferrate anions are decidedly angular. In the series A3[FeO3], the anions in the compounds of the light alkaline cations are chains 1∞[FeO2O2/2]3−, but similar to the isotypic K6[Fe2O6] and to Cs6[Fe2O6] the new ferrate Rb6[Fe2O6] (K6Fe2O6 structure type, space group C2/m, a=741.8(2), b=1148.7(2), c=680.08(12) pm, β =103.65(2)°, Z = 4, R1 = 0.0370) contains isolated binuclear anions [O2FeO2FeO2]6− composed of two edge sharing [FeO4] tetrahedra. The new potassium ferrate of the series A4[Fe2O5], K4[Fe2O5] (space group P21/c, a = 645.91(14), b = 593.69(13), c = 1003.0(2) pm, β = 103.124(4)°, Z = 4, R1 = 0.0355), constitutes a new structure type, but its structure is still closely related to the Na compound, which crystallizes in the isomorphous subgroup P21/n with a doubled a axis. Both compounds are phylloferrates with layers 2∞[Fe2O5]4− consisting of six-membered rings of [FeO4] tetrahedra. In contrast, Rb4[Fe2O5] contains chains of vertex and edge sharing tetrahedra, so that in both series, A3[FeO3] and A4[Fe2O5], the linkedness of the ferrate tetrahedra increases with the ionic radii of the A counterions.

The isotypic family of the diarsenates MM′As2O7 (M = Sr, Ba; M′ = Cd, Hg)

2016 ◽  
Vol 71 (5) ◽  
pp. 403-409 ◽  
Author(s):  
Matthias Weil
Keyword(s):  
Aqueous Solutions ◽  
Single Crystal ◽  
Metal Oxides ◽  
Structure Type ◽  
Hydrothermal Conditions ◽  
Space Group ◽  
X Ray ◽  
Type Space ◽  
Autogenous Pressure

AbstractThe diarsenates MM′As2O7 (M = Sr, Ba; M′ = Cd, Hg) were prepared under hydrothermal conditions (~200 °C, autogenous pressure), starting from As2O5 and the corresponding metal oxides or precursor compounds thereof in aqueous solutions. Structure analyses on the basis of single crystal X-ray data revealed the four structures to be isotypic. They are the first diarsenates to crystallize in the triclinic BaZnP2O7 structure type (space group P1̅, Z = 2, a ≈ 5.8 Å, b ≈ 7.3 Å, c ≈ 7.6 Å, α ≈ 101°, β ≈ 91°, γ ≈ 98°). All related MM′As2O7 diarsenates reported so far (M = Sr, Ba, Pb; M′ = Mg, Co, Cu, Zn) crystallize in the monoclinic α-Ca2P2O7 structure type (P21/n, Z = 4). Hence, the size of the divalent M′ cation determines which of the two structure types is adopted.

Structural Refinement and Homogeneity Range of Sm6Al3Si

2007 ◽  
Vol 130 ◽  
pp. 101-106
Author(s):  
Stanislaw Pikus ◽  
Ihor Melnyk ◽  
Roman E. Gladyshevskii
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Homogeneity Range ◽  
Structure Type ◽  
Powder Diffraction Data ◽  
Structural Refinement ◽  
Space Group ◽  
X Ray ◽  
Type Space ◽  
Trigonal Prisms

The structure of the compound Sm6Al3Si was refined from X-ray powder diffraction data (Tb6Al3Si structure type, space group I4/mcm, a = 11.733(1), c = 15.266(2) Å, Z = 8, RB = 0.0569). Its homogeneity range extends from 10 to 22 at.% Si and the following formula Sm6Al3-1.8Si1.0-2.2 is proposed for the compound studied. The Al and Si atoms are surrounded by Sm atoms forming trigonal prisms, square prisms and antiprisms.

scholarly journals An X-ray analysis of the nickel-aluminium system

1937 ◽  
Vol 159 (896) ◽  
pp. 56-72 ◽  
Keyword(s):  
Solid Solution ◽  
Phase Equilibrium ◽  
Equilibrium Diagram ◽  
Phase Equilibrium Diagram ◽  
Miscibility Gap ◽  
X Ray

An X-ray analysis of the nickel-aluminium system has been made. A comprehensive series of powder photographs were taken of slowly cooled alloys, and in addition some quenching experiments were made on the nickel-rich alloys. In several important particulars the results differ from the phase-equilibrium diagram published by Gwyer (1908) (fig. 1 a ). This diagram has therefore been modified in the direction indicated by our work (fig. 1 b ). The solid solution of aluminium in nickel shown by Gwyer has been found to contain a miscibility gap at room temperatures. The α -phase, which is a face-centred cubic solid solution of aluminium in nickel, extends to 89 atomic % of nickel at room temperatures. The α' -phase, which is a facecentred cubic solid solution closely corresponding to the composition Ni 3 Al, has a superlattice (Westgren and Ekman 1930), nickel atoms occupying centres of cube faces and aluminium atoms cube corners. Quenching extends the range of the α -phase until in alloys quenched from 1100° there is no break between the α and α' structures.

Kristallstruktur von K4O(CN)2 / Crystal Structure of K4O(CN)2

1992 ◽  
Vol 47 (12) ◽  
pp. 1746-1748 ◽  
Author(s):  
Christian Hardt ◽  
Petra Vogt ◽  
Horst Sabrowsky
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Structure Type ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Type Space

Colorless K4O(CN)2 has been prepared. The compound crystallizes in the tetragonal anti-K2NiF4 structure type (space group I4/mmm) with a = 515.5(1) and c = 1606.7(3) pm, Z = 2. The structure was determined by single crystal X-ray diffraction, R = 3.35%.

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