Crystalline structure of Ba2YCu0.25W0.75O6: A member of the new set of Ba2YzCuxW1−xO6 solid solutions

1996 ◽  
Vol 11 (1) ◽  
pp. 42-44 ◽  
Author(s):  
Bokhimi ◽  
A. Morales ◽  
A. Garci´a-Ruiz
Keyword(s):  
Solid Solution ◽  
Crystalline Structure ◽  
Solid Solutions ◽  
Local Environment ◽  
Unit Cell ◽  
Ordered Structure ◽  
Space Group ◽  
First Approximation ◽  
And Tungsten

A model for the crystalline structure of Ba2YCu0.25W0.75O6 solid solution is given. The model proposed a perovskite ordered structure, with a cubic unit cell made from eight perovskite-like units and having a symmetry described by the space group Fm3m. The crystalline structure was refined by the Rietveld technique, giving RF=0.048 for 82 reflections. The solid solution was characterized by the following parameters: Z=4, Mr=613.2, a=8.43630(8) Å, V=600.42(1) Å3, Dx=6.78 g cm−3, μ=209.04 mm−1, and F(000)=1047. The model assumed that copper and tungsten atoms, which were ordered with Y atoms, had the same local environment. Therefore, it was only a first approximation to the crystalline structure.

The solid solution TbNiIn1−x Ga x

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Myroslava Horiacha ◽  
Galyna Nychyporuk ◽  
Rainer Pöttgen ◽  
Vasyl Zaremba
Keyword(s):  
Solid Solution ◽  
Unit Cell ◽  
Type Structure ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Structure Space ◽  
Arc Melting

Abstract Phase formation in the solid solution TbNiIn1−x Ga x at 873 K was investigated in the full concentration range by means of powder X-ray diffraction and EDX analysis. The samples were synthesized by arc-melting of the pure metals with subsequent annealing at 873 K for one month. The influence of the substitution of indium by gallium on the type of structure and solubility was studied. The solubility ranges have been determined and changes of the unit cell parameters were calculated on the basis of powder X-ray diffraction data: TbNiIn1–0.4Ga0–0.6 (ZrNiAl-type structure, space group P 6 ‾ 2 m $P‾{6}2m$ , a = 0.74461(8)–0.72711(17) and c = 0.37976(5)–0.37469(8) nm); TbNiIn0.2–0Ga0.8–1.0 (TiNiSi-type structure, space group Pnma, а = 0.68950(11)–0.68830(12), b = 0.43053(9)–0.42974(6), с = 0.74186(10)–0.73486(13) nm). The crystal structures of TbNiGa (TiNiSi type, Pnma, a = 0.69140(5), b = 0.43047(7), c = 0.73553(8) nm, wR2=0.0414, 525 F 2 values, 21 variables), TbNiIn0.83(1)Ga0.17(1) (ZrNiAl type, P 6 ‾ 2 m $P‾{6}2m$ , a = 0.74043(6), c = 0.37789(3) nm, wR2 = 0.0293, 322 F 2 values, 16 variables) and TbNiIn0.12(2)Ga0.88(2) (TiNiSi type, Pnma, a = 0.69124(6), b = 0.43134(9), c = 0.74232(11) nm, wR2 = 0.0495, 516 F 2 values, 21 variables) have been determined. The characteristics of the solid solutions and the variations of the unit cell parameters are briefly discussed.

scholarly journals The solid solutions of rebulite and jankovićite in the phase system Tl2S-As2S3-Sb2S3

2015 ◽  
Vol 34 (1) ◽  
pp. 125
Author(s):  
Tonci Balic-Zunic ◽  
Yves Moëlo ◽  
Ljiljana Karanović ◽  
Peter Berlepsch
Keyword(s):  
Crystal Structure ◽  
Solid Solution ◽  
Solid Solutions ◽  
Unit Cell ◽  
Phase System ◽  
Structural Topology ◽  
Coordination Polyhedra ◽  
Ideal Composition ◽  
End Members ◽  
Compositional Line

Syntheses along the Tl<sub>5</sub>(As,Sb)<sub>13</sub>S<sub>22</sub> compositional line in the Tl<sub>2</sub>S-As<sub>2</sub>S<sub>3</sub>-Sb<sub>2</sub>S<sub>3</sub> phase system showed that the compositional range of rebulite extends from  Tl<sub>5</sub>As<sub>9.5</sub>Sb<sub>3.5</sub>S<sub>22</sub> to Tl<sub>5</sub>As<sub>7.75</sub>Sb<sub>5.25</sub>S<sub>22</sub>. The Sb-rich end-member is in equilibrium with jankovićite of ideal composition Tl<sub>5</sub>Sb<sub>7.5</sub>As<sub>5.5</sub>S<sub>22</sub>. It is considered to be the As-rich end-member of the jankovićite solid solution. The crystal structure analyses of crystals from the As and Sb end-members of rebulite show that the Sb/As substitution is present in Sb3, Sb4, Sb5, As1 and As2 structural sites. Of them, Sb3 is always Sb dominated whereas other four vary from As- to Sb-dominated over the range of the solid solution. The change of the structural topology from jankovićite to rebulite, the closely related but not identical structures, is explained through necessity to accommodate the smaller volumes of the As coordination polyhedra and is accomplished through unit-cell twinning over the periodic (001)<sub>reb</sub> twin boundaries. The As end-member of the rebulite solid solution is in equilibrium with the phase of Tl<sub>2.4</sub>Sb<sub>0.68</sub>As<sub>7.18</sub>S<sub>13</sub> ideal composition, interpreted as imhofite.

Geikielite–ecandrewsite solid solutions: synthesis and crystal structures of the Mg1−x Zn x TiO3 (0 ≤ x ≤ 0.8) series

2004 ◽  
Vol 60 (5) ◽  
pp. 496-501 ◽  
Author(s):  
Ruslan P. Liferovich ◽  
Roger H. Mitchell
Keyword(s):  
Solid Solution ◽  
Crystal Structures ◽  
Solid Solutions ◽  
Ambient Pressure ◽  
Unit Cell ◽  
Solid Solution Series ◽  
Coordination Polyhedra ◽  
Cell Parameters ◽  
Solution Series ◽  
Zn Content

The crystal structures of members of the geikielite–ecandrewsite solid solution series, Mg1 − x Zn x TiO3 (0 ≤ x ≤ 0.8 a.p.f.u. Zn; a.p.f.u. = atoms per formula unit), synthesized by ceramic methods in air at ambient pressure, have been characterized by Rietveld analysis of X-ray powder diffraction patterns. These synthetic titanates adopt an ordered R\overline 3 structure similar to that of ilmenite. The maximum solubility of Zn in MgTiO3 is considered to be ∼ 0.8 a.p.f.u. Zn, as compounds with greater Zn content could not be synthesized at ambient conditions. Data are given for the cell dimensions and atomic coordinates, together with bond lengths, volumes and distortion indices for all the coordination polyhedra. Within the solid-solution series unit-cell parameters and unit-cell volumes increase with Zn content. All compounds consist of distorted (Mg,Zn)O6 and TiO6 polyhedra and, in common with geikielite and ilmenite (sensu lato), TiO6 polyhedra are distorted to a greater extent than (Mg,Zn)O6. The displacements of (Mg,Zn) and Ti from the centers of their coordination polyhedra vary insignificantly with increasing Zn content. The interlayer distance across the vacant octahedral site in the TiO6 layer decreases slightly with the entry of the larger Zn2+ cation into the vi A site. The empirically obtained upper limit of the Goldschmidt tolerance factor (t) for A 2+ BO3 compounds adopting an ordered R\overline 3 structure is 0.755. The absence of natural solid solutions between geikielite and ecandrewsite seems to be due to the contrasting geochemistry of Mg and Zn rather than for crystallochemical reasons.

Monazite structure from dehydrated CaSeO4·2H2O

2010 ◽  
Vol 74 (1) ◽  
pp. 127-139 ◽  
Author(s):  
W. A. Crichton ◽  
H. Müller ◽  
M. Merlini ◽  
T. Roth ◽  
C. Detlefs
Keyword(s):  
High Temperature ◽  
Structural Stability ◽  
Solid Solutions ◽  
Unit Cell ◽  
Intermediate Temperature ◽  
Type Structure ◽  
Space Group ◽  
Temperature Form ◽  
High Temperature Form

AbstractThe structure of the high-temperature form of CaSeO4, formed by dehydration of the gyspum-type structure dihydrate is presented. The material is equivalent to that described previously as a P212121 form, but is however, a monazite with unit cell a = 6.85661(16) Å, b = 7.04962(15) Å, c = 6.68817(15) Å and β = 104.2675(21)° in space group P121/n1. Also presented is evidence for two intermediate trigonal and pseudo-trigonal phases related to the structurally similar minerals rhabdophane, bassanite, and γ-CaSO4. This result permits closer comparisons between intermediate-temperature structures of the selenate with related sulphates, and orthophosphates with a view to extending structural stability via synthesis of solid-solutions.

Doping Strategies of Bi (Ti0.5Ni0.5)O3 for Increased Performance in BiFeO3

2014 ◽  
Vol 1004-1005 ◽  
pp. 358-361
Author(s):  
Zheng Zheng Ma ◽  
Jian Qing Li ◽  
Zi Peng Chen ◽  
Xiao Jun Hu
Keyword(s):  
Crystal Structure ◽  
Solid Solution ◽  
Magnetic Properties ◽  
Solid Solutions ◽  
Perovskite Structure ◽  
Room Temperature ◽  
Ferroelectric Properties ◽  
Hysteresis Loops ◽  
Space Group ◽  
Substituted 1

Investigation of crystal structure, dielectric, magnetic and local ferroelectric properties of the diamagnetically substituted (1-x)BiFeO3-xBi (Ti0.5Ni0.5)O3solid solutions samples have been carried out. The solid solutions have been found to possess a rhombohedrally distorted perovskite structure described by the space group R3c. Compared with pure BiFeO3compound, both ferroelectric and magnetic properties are much improved by solid solution with Bi (Ti0.5Ni0.5)O3with saturation hysteresis loops observed. Among all the samples, thex=0.1 samples shows the optimal ferromagnetism with Mr~0.56531emμ/g and the optimal ferroelectricity with Pr~5.767μC/cm2 at room temperature.

Monazite end members and solid solutions: synthesis, unit-cell characteristics, and utilization as microprobe standards

1989 ◽  
Vol 53 (369) ◽  
pp. 120-123 ◽  
Author(s):  
J. M. Montel ◽  
F. Lhote ◽  
J. M. Claude
Keyword(s):  
Solid Solution ◽  
Experimental Study ◽  
Solid Solutions ◽  
Unit Cell ◽  
Solid Solution Series ◽  
Solution Series ◽  
End Members ◽  
Characteristics And Utilization

The synthesis of monazite was first reported by Radominsky (1875). Since then various methods have been used to synthesize various end members of the monazite solid solution series, mainly CePO4 and LaPO4 (e.g. Anthony, 1957, 1965). As part of an experimental study dealing with the solubility of monazite in granitic melts (Montel, 1986, 1987, and in prep.), the synthesis of some of the end members, as well as solid solutions, was achieved.

Monazite-huttonite solid-solutions from the Vico Volcanic Complex, Latium, Italy

1996 ◽  
Vol 60 (402) ◽  
pp. 751-758 ◽  
Author(s):  
Giancarlo Della Ventura ◽  
Annibale Mottana ◽  
Gian Carlo Parodi ◽  
Mati Raudsepp ◽  
Fabio Bellatreccia ◽  
...  
Keyword(s):  
Solid Solution ◽  
Distribution Pattern ◽  
Solid Solutions ◽  
Electron Probe ◽  
Divalent Cations ◽  
Volcanic Complex ◽  
Crystal Chemical ◽  
Space Group ◽  
Single Grain ◽  
Anionic Groups

AbstractThe crystal-chemical relationships occurring within a single grain of monazite-(Ce) from Vetralla, Vico Volcanic Complex, north of Rome, are outlined. The sample is from a miarolitic cavity in a holocrystalline ejectum consisting of K-feldspar plus minor plagioclase, mica and Fe-oxides, collected from a pyroclastic explosive level. The Gandolfi film (Cu-Kα radiation) can be indexed in space group P21/n with a = 6.816(4); b = 6.976(4); c = 6.471(3) Å; β = 103.63(3)°; V = 299.0(6) Å3. Electron-probe microanalyses plot within the field of monazite along the huttonite-monazite edge of the huttonite-monazite-brabantite triangle. Despite patchy and irregular zoning, the grain shows a clear enrichment towards pure monazite at the outer rim. A constant Th:Si ratio of 1:1 indicates the existence of a simple solid-solution between huttonite and monazite. The substitution can be written as Th4+ + Si4+ → REE3+ + P5+ without requiring any electrostatic compensation by divalent cations, or by anionic groups. The REE distribution pattern is compatible with that of monazites from syenitic rocks.

scholarly journals The crystalline structure of benzene

1932 ◽  
Vol 135 (827) ◽  
pp. 491-498 ◽  
Keyword(s):  
Benzene Ring ◽  
Crystalline Structure ◽  
Unit Cell ◽  
Space Group ◽  
Preliminary Results ◽  
Amount Of Information ◽  
Previous Communication ◽  
Cell Dimensions

In a previous communication the writer gave the preliminary results of an investigation on the structure of solid benzene. It may be recalled that the unit cell was found to have the following dimensions at —22° C. ; a = 7·44, b = 9·65, c = 6·81 Å. U., while the space-group was determined as Q h 15 (orthorhombic bipyramidal). The unit cell contains four molecules, the molecules being centro-symmetrical. Since the publication of these results a certain amount of information has been obtained by other investigators. Bruni and Natta took powder photographs of benzene which confirmed the above values of the cell-dimensions; this is very satisfactory, since previous workers (Broomé and Eastman) had obtained axial ratios which did not agree particularly well with each other’s or with the writer’s. Mrs. Lonsdale has shown that in hexamethylbenzene the benzene ring is planar, the diameter of the atoms being 1·42 Å. U. More recently she has examined hexachlorobenzene, and although in this case the investigation did not yield quite such definite results, it was shown that if the ring is planar then again the diameter of the atoms must be 1·42 Å. U.

Structure of Gd(5-x)HoxSi4 Solid Solutions

2008 ◽  
Vol 368-372 ◽  
pp. 632-634 ◽  
Author(s):  
Y.F. Zhou ◽  
Yong Mei Hao ◽  
Zhong Bo Hu
Keyword(s):  
Powder Diffraction ◽  
Solid Solutions ◽  
Systematic Study ◽  
Diffraction Method ◽  
Unit Cell ◽  
Orthorhombic Structure ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

A new systematic study of the formation and structure of solid solutions Gd (5-x)HoxSi4 (x = 1.0-5.0) has been performed. By X-ray powder diffraction method, it was found that these compounds all crystallize in orthorhombic structure with space group Pnma and the cell parameters a, b, c and the volume of unit cell are correlated with the holmium content.

X-ray study of CuGa x In1−x Se2 solid solutions

1989 ◽  
Vol 22 (6) ◽  
pp. 578-583 ◽  
Author(s):  
D. K. Suri ◽  
K. C. Nagpal ◽  
G. K. Chadha
Keyword(s):  
Solid Solution ◽  
Binary System ◽  
Crystallite Size ◽  
Solid Solutions ◽  
Lattice Parameters ◽  
Chalcopyrite Structure ◽  
Space Group ◽  
X Ray ◽  
Structure Space ◽  
A Value

The semiconducting compound CuGa x In1 − x Se2 crystallizes in the chalcopyrite structure (space group I{\bar 4}2d, Z = 4). The X-ray powder data for x = 1, 0.75, 0.6, 0.5, 0.4, 0.25 and 0.0 have been collected and it is found that the lattice parameters a and c and their ratio c/a vary linearly with x. Thus the composition of any chalcopyrite in the pseudo-binary system CuGaSe2 and CuInSe2 can be obtained from the accurate lattice parameters. The crystallite size determined from the (112) plane is minimum for x = 0.50 (~ 1000 Å) and away from x = 0.50 it increases. A value of u = 0.240 (5) has been established for fixing the Se-atom positions in the CuGa0.5In0.5Se2 solid solution. The JCPDS Diffraction File No. for CuInSe2 is 40-1487 and for CuGa0.5In0.5Se2 is 40-1488.

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