X-ray diffraction patterns for BaR2PdO5 (R=Nd, Sm, Eu, and Gd)

1996 ◽  
Vol 11 (1) ◽  
pp. 9-12
Author(s):  
W. Wong-Ng

Calculated patterns for the BaR2PdO5 series, in which X is Pd and R=Nd, Sm, Eu, or Gd, have been prepared for materials characterization until experimental patterns can be determined. These compounds are isostructural to the superconductor related “brown phases” BaLa2CuO5 and BaNd2CuO5, which are tetragonal with space group P4/mbm, Z=4. The cell parameters of the Eu and Gd compounds were derived from the La and Nd analogs. The calculated patterns of these four compounds compared well to an experimental pattern of BaNd2CuO5.

1982 ◽  
Vol 26 ◽  
pp. 63-72 ◽  
Author(s):  
Nikos P. Pyrros ◽  
Camden R. Hubbard

The production of standard x-ray diffraction patterns at NBS imposes special requirements in the data processing of powder patterns. The patterns should be complete and have an overall accuracy of better than 0.01 degree two theta. To ensure completeness all the observable peaks should be indexed. To make certain that the sample is a pure phase, weak peaks have to be identified as well.The indexing of all the peaks implies that the cell constants must be known and there should be a good agreement between all the calculated and observed peak positions. In practice this is achieved by a least-squares refinement of the unit cell parameters. This serves as a test of the assumed unit cell and also as an interpretation of the observed peaks. Finally, an attempt is made to identify the space group. This step also requires the identification of weak peaks. The agreement of a known space group with the observed reflections further confirms the purity of the sample.


2004 ◽  
Vol 19 (4) ◽  
pp. 378-384
Author(s):  
A. Rafalska-Lasocha ◽  
M. Grzywa ◽  
B. Włodarczyk-Gajda ◽  
W. Lasocha

The X-ray diffraction patterns of two organic acids 1-naphthalenesulfonic acid dihydrate and 2-naphthalenesulfonic acid hydrate were measured at room temperature. Complexes of these acids with 1,8-bis(dimethylamino)naphthalene (DMAN) were synthesized, purified and investigated by means of X-ray powder diffraction. 1-Naphthalenesulfonic acid dihydrate as well as its complex with 1,8-bis(dimethylamino)naphthalene crystallize in the monoclinic system with unit cell parameters refined to a=0.91531(8) nm, b=0.7919(1) nm, c=0.8184(1) nm, β=101.618(9)° space group P21/m (11) and a=1.7781(4) nm, b=2.0122(4) nm, c=1.2337(2) nm, β=96.54(3)°, space group C2/m (12), respectively. 2-Naphthalenesulfonic acid hydrate crystallizes in the orthorhombic system with a=2.2749(3) nm, b=0.7745(1) nm, c=0.591 36(9) nm, space group Pnma, whereas its complex with 1,8-bis(dimethylamino)naphthalene crystallizes in the triclinic system a=1.3969(6) nm, b=1.4292(5) nm, c=1.1741(6) nm, α=90.93(3)°, β=98.14(3)°, γ=113.93(3)°, space group P-1 (2).


2002 ◽  
Vol 17 (3) ◽  
pp. 234-237 ◽  
Author(s):  
S. Ferdov ◽  
V. Kostov-Kytin ◽  
O. Petrov

Synthetic analogues of the minerals natisite and for the first time of paranatisite were prepared hydrothermally at 200 °C in the system Na2O–TiO2–SiO2–H2O. The obtained powder x-ray diffraction (XRD) patterns were interpreted by the Powder Data Interpretation (PDI) software package. As a result improved indexing and unit cell parameters refinements of these two phases were achieved. Synthetic natisite is tetragonal, space group—P4/nmm, a=0.649 67(8) nm, c=0.508 45(11) nm, V=0.214 50(10) nm3, Z=2, Dcal=3.13 g.cm−1, F30=37.48, M20=52.79. Synthetic paranatisite is orthorhombic, space group—Pmma, a=0.983 86(29) nm, b=0.919 23(19) nm, c=0.481 84(12) nm, V=0.435 78(19) nm3, Z=1, Dcal=3.01 g.cm−1, F30=16.42, M20=29.21.


2011 ◽  
Vol 26 (4) ◽  
pp. 346-349 ◽  
Author(s):  
M. A. Macías ◽  
J. A. Henao ◽  
Lina María Acosta ◽  
Alirio Palma

The 6,8-dimethyl-cis-2-vinyl-2,3,4,5-tetrahydro-1H-benzo[b]azepin-4-ol (2a) (Chemical formula C14H19NO) and 8-chloro-9-methyl-cis-2-(prop-1-en-2-yl)-2,3,4,5-tetrahydro-1H-benzo[b]azepin-4-ol (2b) (Chemical formula C14H18ClNO) were prepared via the reductive cleavage of the bridged N-O bond of the corresponding 1,4-epoxytetrahydro-1-benzazepines. The X-ray powder diffraction patterns for the new compounds were obtained. The compound 2a was found to crystallize in an orthorhombic system with space group Pmn21 (No. 31), refined unit-cell parameters a = 19.422(6) Å, b = 6.512(3) Å, c = 9.757(4) Å and V = 1234.0(5) Å3. The compound 2b was found to crystallize in a monoclinic system with space group P21/m (No. 11), refined unit-cell parameters a = 17.570(4) Å, b = 8.952(3) Å, c = 14.985(4) Å, β = 101.66(2)°, and V = 2308.3(9) Å3.


1990 ◽  
Vol 5 (1) ◽  
pp. 27-32 ◽  
Author(s):  
W. Wong-Ng ◽  
C.K. Chiang ◽  
B. Paretzkin ◽  
E.R. Fuller

AbstractThe superconductor related phases Ba3R3Cu6O14+x(or Ba2−zR1+zCu3O7+x, with z=0.5), where R = Pr, Nd, Sm, and Eu, have been prepared and characterized by X-ray powder diffraction, ac magnetic susceptibility measurement, resistivity measurement and thermogravimetric analysis (TGA). Attempts to make corresponding compounds with R = Gd, Dy, Y, Er, and Lu were not successful; they do not appear to form for rare-earth elements, R, with an ionic size smaller than Eu. The oxygen content of the successful materials was estimated by TGA. The Ba3R3Cu6Cu14+xcompounds which were sintered at 950°C and annealed in oxygen at 550°C were found to be nonsuperconducting above 10K. Previously reported results for the R=La compound have indicated that it was superconducting with a transition temperature of 15K The oxidation-reduction behavior of the Ba3R3Cu6O14+xmaterials is similar to that of the superconductor phases Ba2RCu3O6+x.These present isostructural compounds are tetragonal with a space group of P4/mmm. The cell parameters range from a = 3.8612(4), c = 11.5624(14) Å, V = 172.38(4) Å3in the Eu compound to a = 3.8893(3), c = 11.6370(11) Å, and V = 176.03(3) Å3in the Pr compound. The standard X-ray diffraction patterns of these materials are given.


Author(s):  
Fang Lu ◽  
Bei Zhang ◽  
Yong Liu ◽  
Ying Song ◽  
Gangxing Guo ◽  
...  

Phytases are phosphatases that hydrolyze phytates to less phosphorylatedmyo-inositol derivatives and inorganic phosphate. β-Propeller phytases, which are very diverse phytases with improved thermostability that are active at neutral and alkaline pH and have absolute substrate specificity, are ideal substitutes for other commercial phytases. PhyH-DI, a β-propeller phytase fromBacillussp. HJB17, was found to act synergistically with other single-domain phytases and can increase their efficiency in the hydrolysis of phytate. Crystals of native and selenomethionine-substituted PhyH-DI were obtained using the vapour-diffusion method in a condition consisting of 0.2 Msodium chloride, 0.1 MTris pH 8.5, 25%(w/v) PEG 3350 at 289 K. X-ray diffraction data were collected to 3.00 and 2.70 Å resolution, respectively, at 100 K. Native PhyH-DI crystals belonged to space groupC121, with unit-cell parametersa = 156.84,b = 45.54,c = 97.64 Å, α = 90.00, β = 125.86, γ = 90.00°. The asymmetric unit contained two molecules of PhyH-DI, with a corresponding Matthews coefficient of 2.17 Å3 Da−1and a solvent content of 43.26%. Crystals of selenomethionine-substituted PhyH-DI belonged to space groupC2221, with unit-cell parametersa = 94.71,b= 97.03,c= 69.16 Å, α = β = γ = 90.00°. The asymmetric unit contained one molecule of the protein, with a corresponding Matthews coefficient of 2.44 Å3 Da−1and a solvent content of 49.64%. Initial phases for PhyH-DI were obtained from SeMet SAD data sets. These data will be useful for further studies of the structure–function relationship of PhyH-DI.


1964 ◽  
Vol 42 (10) ◽  
pp. 1886-1889 ◽  
Author(s):  
B. Swaroop ◽  
S. N. Flengas

The crystal structure of zirconium trichloride was determined from X-ray diffraction patterns. Zirconium trichloride belongs to the [Formula: see text]space group. The dimensions of the main cell at room temperature are: a = 5.961 ± 0.005 Å and c = 9.669 ± 0.005 Å.The density of zirconium trichloride was measured and gave the value of 2.281 ± 0.075 g/cm3 while, from the X-ray calculations, the value was found to be 2.205 g/cm3.


2021 ◽  
Vol 103 (3) ◽  
pp. 67-73
Author(s):  
A.A. Toibek ◽  
◽  
K.T. Rustembekov ◽  
D.A. Kaikenov ◽  
M. Stoev ◽  
...  

For the first time, double gadolinium tellurites of the composition GdMIITeO4.5 (MII — Sr, Ba) were synthesized by the solid-phase method. The solid-phase synthesis of samples was carried out from decrepitated gadolinium (III) and tellurium (IV) oxides, strontium, and barium carbonates according to the standard ceramic technology. The synthesis was carried out in the temperature range of 800-1100 °C. The samples obtained were confirmed by X-ray phase analysis. X-ray phase analysis was carried out on an Empyrean instrument in the XRDML Pananalitical format. The intensity of the diffraction maxima was estimated on a 100-point scale. X-ray diffraction patterns indexing of the powder of gadolinium tellurites — alkaline earth metals studied were carried out by the homology method. The reliability and correctness of the results of indexing the X-ray diffraction patterns are confirmed by the good agreement between the experimental and calculated values of the interplanar distances (d) and the agreement between the values of the X-ray and pycnometric densities. It was found that compounds GdSrTeO4.5 and GdBaTeO4.5 crystallize in the monoclinic system and have the unit cell parameters, namely GdSrTeO4.5 — a = 12.7610, b = 10.4289, c = 8.6235 Å, V° = 1141.83 Å3, β = 95.77°, Z = 5, ρrent. = 3.22, ρpikn. = (3.10±0.09) g/cm3; GdBaTeO4.5 — a = 15.7272, b = 15.8351, c = 7.1393 Å, V° = 1769.72 Å3, β = 95.53°, Z = 8, ρrent = 3.71, ρpick = (3.61±0.10) g/cm3. Using the Landiya method, the standard heat capacities of the compounds were estimated from the calculated values of the standard entropies, and the temperature dependences of the heat capacities of the gadolinium tellurites synthesized were determined in the temperature range of 298–850 K.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Myroslava Horiacha ◽  
Galyna Nychyporuk ◽  
Rainer Pöttgen ◽  
Vasyl Zaremba

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.


Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2326
Author(s):  
Sungjun Yang ◽  
Sangmoon Park

Optical materials composed of La1-p-qBipEuqO0.65F1.7 (p = 0.001–0.05, q = 0–0.1) were prepared via a solid-state reaction using La(Bi,Eu)2O3 and NH4F precursors at 1050 °C for two hours. X-ray diffraction patterns of the phosphors were obtained permitting the calculation of unit-cell parameters. The two La3+ cation sites were clearly distinguished by exploiting the photoluminescence excitation and emission spectra through Bi3+ and Eu3+ transitions in the non-stoichiometric host lattice. Energy transfer from Bi3+ to Eu3+ upon excitation with 286 nm radiation and its mechanism in the Bi3+- and Eu3+-doped host structures is discussed. The desired Commission Internationale de l’Eclairage values, including emissions in blue-green, white, and red wavelength regions, were obtained from the Bi3+- and Eu3+-doped LaO0.65F1.7 phosphors.


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