scholarly journals Characterisation of K-doped Bi4V2O11 by combined XRD and EPMA: A cautionary tale

1997 ◽  
Vol 12 (4) ◽  
pp. 245-247 ◽  
Author(s):  
C. K. Lee ◽  
A. M. Coats ◽  
A. R. West
Keyword(s):  
Powder Diffraction ◽  
Electron Probe ◽  
Solid Electrolytes ◽  
Single Phase ◽  
Variable Composition ◽  
Cautionary Tale ◽  
Phase Purity ◽  
X Ray ◽  
Phase Pure ◽  
Doped Materials

A comparison of X-ray powder diffraction and electron probe microanalyses on samples of Na- and K-doped Bi4V2O11 (BIMEVOX) solid electrolytes indicates some of the problems associated with using XRD to assess phase purity, especially in materials of variable composition such as BIMEVOXes. In this study both the Na- and K-doped materials appeared phase pure by XRD. EPMA indicated the Na-doped materials to be single phase with their expected compositions while the K-containing materials were not phase pure with very little K present in the main BIMEVOX phase.

scholarly journals Structural Chemistry of Some Phases in The YC-Ni-B System

1994 ◽  
Vol 376 ◽  
Author(s):  
B. C. Chakoumakos
Keyword(s):  
Powder Diffraction ◽  
Single Phase ◽  
Rietveld Analysis ◽  
Neutron Powder Diffraction ◽  
The Other ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Neutron Powder Diffraction Data ◽  
Arc Melting ◽  
Phase Pure

ABSTRACTNiB, monoclinic Ni4B3, Ni2B and Ni3B were prepared by arc-melting and their roomtemperature crystal structures were refined by Rietveld analysis of neutron powder diffraction data. The NiB refinement is altogether new data. Although the B atoms in NiB form characteristic zigzag chains, the primary coordination of each atom by atoms of the other kind is similar and distinctively sevenfold, with one short (2.117 Å), two intermediate (2.152 Å), and four long (2.163 Å) bonds. Other samples with stoichiometries (YC)nNi2B2, n = 3, 4, did not yield single-phase material, but both x-ray and neutron powder diffraction suggest that the n = 4 structure is present in both of these samples. Phase-pure samples of these homologues may require non-stoichiometry and a more controlled thermal history than is attainable by arc melting.

Crystal structure and X-ray powder diffraction pattern of Ti2ZrAl

2000 ◽  
Vol 15 (3) ◽  
pp. 189-190 ◽  
Author(s):  
D. Sornadurai ◽  
B. Panigrahi ◽  
V. S. Sastry ◽  
Ramani
Keyword(s):  
Crystal Structure ◽  
Diffraction Pattern ◽  
Powder Diffraction ◽  
Single Phase ◽  
Xrd Analysis ◽  
Melting Method ◽  
X Ray ◽  
Structure Space ◽  
Arc Melting ◽  
Phase Pure

We report precision X-ray powder-diffraction (XRD) data of single phase pure Ti2ZrAl. Ti2ZrAl samples were prepared by an arc melting method and annealed at 1000 °C for 30 days. XRD analysis was carried out on these samples and it was found that Ti2ZrAl has a DO19 structure (space group P63/mmc, No. 194). The lattice parameters are found to be a=5.961±0.001 Å and c=4.793±0.001 Å.

SYNTHESIS OF THE SINGLE 107 K SUPERCONDUCTING PHASE IN THE Pb-Bi-Sr-Ca-Cu-O SYSTEM

1989 ◽  
Vol 03 (07) ◽  
pp. 571-574 ◽  
Author(s):  
F. SHI ◽  
S.Z. ZHOU ◽  
J. DOU ◽  
Z.H. SHI ◽  
L. TANG ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
Single Phase ◽  
Xrd Analysis ◽  
Superconducting Phase ◽  
Xrd Pattern ◽  
Phase Purity ◽  
X Ray ◽  
Long Period ◽  
Orthorhombic Cell ◽  
First Time

The single phase of the high-Tc phase (107 K) in Bi-based system has been synthesized successfully for the first time by partial substituting of Pb for Bi and combined with adding more Ca, Cu based on Bi 2 Sr 2 Ca 2 Cu 3 O y formula. A long period of sintering at 880°C is necessary to get the sample and its good phase purity are proved by a.c. susceptibility measurement and the X-ray powder diffraction (XRD) analysis. The XRD pattern can be well assigned to an orthorhombic cell with a=5.418 Å, b=5.346 Å and c=37.10 Å.

Synthesis and characterisation of transition metal substituted barium hollandite ceramics

2006 ◽  
Vol 932 ◽  
Author(s):  
Neil C. Hyatt ◽  
Martin C. Stennett ◽  
Steven G. Fiddy ◽  
Jayne S. Wellings ◽  
Sian S. Dutton ◽  
...  
Keyword(s):  
Transition Metal ◽  
Oxidation State ◽  
Powder Diffraction ◽  
Single Phase ◽  
Maximum Density ◽  
Processing Conditions ◽  
Metal Oxidation ◽  
Exafs Data ◽  
X Ray ◽  
Oxygen Atoms

ABSTRACTA range of transition metal bearing hollandite phases, formulated Ba1.2B1.2Ti6.8O16 (B2+ = Mg, Co, Ni, Zn, Mn) and Ba1.2B2.4Ti5.6O16 (B3+ = Al, Cr, Fe) were prepared using an alkoxide - nitrate route. X-ray powder diffraction demonstrated the synthesis of single phase materials for all compositions except B = Mn. The processing conditions required to produce > 95 % dense ceramics were determined for all compositions, except B = Mg for which the maximum density obtained was > 93 %. Analysis of transition metal K-edge XANES data confirmed the presence of the targeted transition metal oxidation state for all compositions except B = Mn, where the overall oxidation state was found to be Mn3+. The K-edge EXAFS data of Ba1.2B1.2Ti6.8O16 (B = Ni and Co) were successfully analysed using a crystallographic model of the hollandite structure, with six oxygen atoms present in the first co-ordination shell at a distance of ca. 2.02Å. Analysis of Fe K-edge EXAFS data of Ba1.2B2.4Ti5.4O16 revealed a reduced co-ordination shell of five oxygens at ca. 1.99Å.

Synthesis, Structure, and Characterization of La1−xBax (0 ≤ x ≤ 1)

1992 ◽  
Vol 271 ◽  
Author(s):  
Joseph E. Sunstrom ◽  
Susan M. Kauzlarich
Keyword(s):  
Magnetic Susceptibility ◽  
Powder Diffraction ◽  
Single Phase ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Temperature Dependent ◽  
X Ray ◽  
Early Transition Metal ◽  
Arc Melting

ABSTRACTThe compounds La1−xBaxTiO3 (0 ≤ × ≤ 1) have been prepared by arc melting stoichiometric amounts of LaTiO3 and BaTiO3. Single phase samples can be made for the entire stoichiometry range. The polycrystalline samples have been characterized by thermal gravimetric analysis, X-ray powder diffraction, and temperature dependent magnetic susceptibility. This series of compounds has been studied as a possible candidate for an early transition metal superconductor.

Synthesis and Characterization of T12Ba2CaCu2O8 and T12Ba2Ca2Cu3O10

1989 ◽  
Vol 169 ◽  
Author(s):  
Lauren E. H. McMills ◽  
Shu Li ◽  
Zhen Zhang ◽  
Martha Greenblatt
Keyword(s):  
Magnetic Susceptibility ◽  
Powder Diffraction ◽  
Single Phase ◽  
Synthesis And Characterization ◽  
Synthetic Method ◽  
Superconducting Properties ◽  
X Ray ◽  
Preparation Conditions ◽  
The Relationship

AbstractSingle-phase samples of T12Ba2CaCu2O8 and T12Ba2Ca2Cu3O10 have been prepared using a reliable and simple synthetic method. Samples were characterized by x-ray powder diffraction, magnetic susceptibility and four probe resistivity methods. The TcR=0 values for T12Ba2CaCu2O8 ranged from 100 to 105K, whereas those for T12Ba2Ca2Cu3O10 ranged from 96 to 107K. The relationship between the superconducting properties and the various preparation conditions are discussed.

Powder diffraction data of two tricydic diazonia diiodide salts used in silver iodide solid electrolytes

1993 ◽  
Vol 8 (3) ◽  
pp. 175-179
Author(s):  
J. Estienne ◽  
O. Cerclier ◽  
J. J. Rosenberg
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Silver Iodide ◽  
Solid Electrolytes ◽  
Rietveld Method ◽  
Powder Diffraction Data ◽  
Organic Salts ◽  
X Ray ◽  
Structure Determinations

Indexed X-ray powder diffraction data are reported for two organic salts with carbon rings having two quaternary nitrogens: diazonia-6,9 dispiro [5.2.5.2] hexadecane and diazonia-6,9 dispiro [5.2.5.3] heptadecane diiodides. For these compounds, which give solid electrolytes when associated with AgI, powder diffraction diagrams calculated by the Rietveld method from single crystal structure determinations are presented and are compared to the experimental diffraction data.

X-ray powder diffraction data of A-formula lanthanum and titanium substituted lead zirconate

2003 ◽  
Vol 18 (3) ◽  
pp. 252-262 ◽  
Author(s):  
Else Breval ◽  
Nichole Wonderling ◽  
Joseph P. Dougherty
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Tetragonal Phase ◽  
Hexagonal Phase ◽  
Lead Zirconate ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Phase Pure

PLZT of the compositions 0≤L≤12, and 0≤T≤10 was studied in order to describe the structure of the phases as a function of composition. This range contains a mixed region with PLZT+La2Zr2O7, an orthorhombic, a rhombohedral (hexagonal) phase, a tetragonal phase, and a mixture of different PLZT phases. Each phase pure composition is described by X-ray diffraction.

scholarly journals The crystal chemistry and electrical properties of Fe doped Ca12Al14O33 (Mayenite)

2021 ◽  
Vol 40 (4) ◽  
pp. 591-597
Author(s):  
S.N. Ude ◽  
C.J. Rawn ◽  
T.T. Meek
Keyword(s):  
Solid State ◽  
Electrical Properties ◽  
Crystal Chemistry ◽  
Powder Diffraction ◽  
Synthesis Method ◽  
Neutron Powder Diffraction ◽  
Solid State Synthesis ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Phase Pure

X-ray and neutron powder diffraction have been used to study the crystal chemistry of Fe doped mayenite (Ca12Al14-xFexO33). Solid- state synthesis was used to prepare Ca12Al14-xFexO33 where x = 0, 0.1, 0.2, 0.5 and 0.6 and the citrate gel route was used to prepare Ca12Al14-xFexO33 where x = 0, 0.05, 0.1, 0.2, 0.3 and 0.4. X-ray powder diffraction data indicate that samples with the same composition but synthesized by the citrate gel route were more likely to be phase pure than samples obtained by traditional solid-state synthesis. The refined lattice parameters were observed to increase with increasing Fe concentration, irrespective of the synthesis method. Refined neutron powder data confirm that Fe is going into Al site rather than Ca site. A 2-point probe was used to measure the electrical properties of the Fe doped citrate gel synthesized samples and showed that the resistivity increases for the Fe doped samples compared to the undoped mayenite.

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