Structural changes occurring upon dehydration of zeolite Rho. A study using neutron powder diffraction and distance-least-squares structural modeling

1984 ◽  
Vol 88 (8) ◽  
pp. 1635-1640 ◽  
Author(s):  
John B. Parise ◽  
David E. Cox
Keyword(s):  
Least Squares ◽  
Powder Diffraction ◽  
Structural Changes ◽  
Structural Modeling ◽  
Neutron Powder Diffraction ◽  
Zeolite Rho ◽  
Rho A

scholarly journals Single-crystal X-ray and neutron powder diffraction investigation of the phase transition in tetrachlorobenzene

2006 ◽  
Vol 62 (2) ◽  
pp. 287-295 ◽  
Author(s):  
Sarah A. Barnett ◽  
Charlotte K. Broder ◽  
Kenneth Shankland ◽  
William I. F. David ◽  
Richard M. Ibberson ◽  
...  
Keyword(s):  
Phase Transition ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Structural Changes ◽  
Neutron Powder Diffraction ◽  
X Ray Diffraction ◽  
Polymorphic Phase Transition ◽  
X Ray ◽  
Apparent Loss ◽  
Two Phases

The polymorphic phase transition of 1,2,4,5-tetrachlorobenzene (TCB) has been investigated using neutron powder diffraction and single-crystal X-ray diffraction. The diffraction experiments show a reversible phase change that occurs as a function of temperature with no apparent loss of sample quality on transition between the two phases. Neutron powder diffraction gives detailed information on the molecular structural changes and lattice parameters from 2 K to room temperature. The structure of the low-temperature form has been elucidated for the first time using single-crystal X-ray diffraction. Comparison of the α and β structures show that they are both based on the same sheet motif, with the differences between the two being very subtle, except in terms of crystal symmetry. Detailed analysis of the structures revealed the changes required for inter-conversion. A computational polymorph search showed that these two sheet structures are more thermodynamically stable than alternative herringbone-type structures.

New Insight into Cation Relocations within the Pores of Zeolite Rho:  In Situ Synchrotron X-Ray and Neutron Powder Diffraction Studies of Pb- and Cd-Exchanged Rho

2001 ◽  
Vol 105 (30) ◽  
pp. 7188-7199 ◽  
Author(s):  
Yongjae Lee ◽  
Barbara A. Reisner ◽  
Jonathan C. Hanson ◽  
Glover A. Jones ◽  
John B. Parise ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
Neutron Powder Diffraction ◽  
X Ray ◽  
Zeolite Rho ◽  
Insight Into

Recognition and Treatment of Background Problems in Neutron Powder Diffraction Refinements

1985 ◽  
Vol 29 ◽  
pp. 131-142 ◽  
Author(s):  
W. H. Baur ◽  
R. X. Fischer
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Neutron Powder Diffraction ◽  
Bragg Scattering ◽  
Powder Diffraction Data ◽  
Bond Lengths ◽  
Neutron Powder Diffraction Data ◽  
Corrected Data ◽  
Zeolite Rho ◽  
Temperature Factors

AbstractIrregular backgrounds in time-of-flight neutron powder diffraction data and nonlinear backgrounds in angle dependent neutron powder diffraction data. were corrected by fitting fifth degree polynomials to those portions of the data most affected. The anomalous background intensities were in both cases due to non Bragg scattering. The polynomial fitting was carried out over a sufficiently widerange of the profile to avoid interfering with the Bragg peaks. The corrected data gave internally consistent results for the crystallographically nonequivalent (Si,Al) -0 (1) and(Si, Al) -0 (2) bond lengths in zeolite rho and compare favorably with previous refinements of this Zeolite in space group Im3m. Internal and external in consistencies of bond lengths are just as diagnostic of refinement difficulties as negative isotropic temperature factors or non positive definite an isotropic temperature factors are.

New different forms of ammonium loaded and partly deammoniated zeolite rho studied by neutron powder diffraction

1989 ◽  
Vol 45 (7) ◽  
pp. 983-989 ◽  
Author(s):  
R. X. Fischer ◽  
W. H. Baur ◽  
R. D. Shannon ◽  
J. B. Parise ◽  
J. Faber ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
Neutron Powder Diffraction ◽  
Zeolite Rho

DETERMINATION OF THE CRYSTAL STRUCTURE OF ERBIUM TITANATE, Er2Ti2O7, BY X-RAY AND NEUTRON DIFFRACTION

1965 ◽  
Vol 43 (10) ◽  
pp. 2812-2826 ◽  
Author(s):  
Osvald Knop ◽  
François Brisse ◽  
Lotte Castelliz
Keyword(s):  
Crystal Structure ◽  
Neutron Diffraction ◽  
Infrared Spectrum ◽  
Least Squares ◽  
Powder Diffraction ◽  
Neutron Powder Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Pyrochlore Type

The crystal structure of erbium titanate, Er2Ti2O7, has been shown by X-ray and neutron powder diffraction to be of the cubic pyrochlore type, with ao = 10.0762 ± 6 Å. Least-squares isotropic refinement based on resolved single reflections gave x(O2) = 0.4200 ± 10 and R = 2.25%. Ionic and neutral X-ray scattering factors gave practically identical results. The six equal Ti—O2 distances in the distorted coordination octahedron of the Ti atom are 1.955 ± 5 Å. The two short (apparent) Er—O distances are 2.1815 ± 5 Å (Er—O1) and 2.471 ± 8 Å (Er—O2). The infrared spectrum of the titanate in the region 1 600 to 250 cm−1 shows features similar to those encountered in the spectra of other simple oxygen compounds of titanium.

scholarly journals Structural changes in YBaCo4O7+δmonitored by variable-temperature neutron powder diffraction

2008 ◽  
Vol 64 (a1) ◽  
pp. C616-C616
Author(s):  
M.V. Valkeapää ◽  
S. Norberg ◽  
S. Eriksson ◽  
S. Hull ◽  
S. Rasanen ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
Structural Changes ◽  
Variable Temperature ◽  
Neutron Powder Diffraction

Local Atomic Structure of Plzt Determined by Real-Space Refinement of Neutron-Powder-Diffraction Data

1994 ◽  
Vol 376 ◽  
Author(s):  
S. Teslic ◽  
T. Egami
Keyword(s):  
Powder Diffraction ◽  
Atomic Structure ◽  
Pair Distribution Function ◽  
Structural Changes ◽  
Real Space ◽  
Neutron Powder Diffraction ◽  
Local Atomic Structure ◽  
Atomic Displacements ◽  
Neutron Powder Diffraction Data ◽  
Pdf Analysis

ABSTRACTThe local atomic structure of (Pb1-x Lax)( Zry Ti1.y)1.x/4O3 (PLZT) has been examined by means of pair-distribution function (PDF) analysis derived from neutron powder diffraction. We find that atoms are displaced from the atomic sites in the average periodic structure by a significant amount. The directions and magnitudes of the atomic displacements in PLZT are very similar to those found in Pb(Mg1/3Nb2/3)O3 (PMN). The short- and intermediate-range structural changes between ferroelectric, relaxor and antiferroelectric PLZT phases were compared.

scholarly journals Direct observation of structural changes near and at the charge-ordering temperature of ilvaite using high-flux neutron powder diffraction

2014 ◽  
Vol 2 (20) ◽  
pp. 3890-3894
Author(s):  
E. R. Williams ◽  
M. T. Weller
Keyword(s):  
Long Range ◽  
Powder Diffraction ◽  
Structural Changes ◽  
Rapid Determination ◽  
Neutron Powder Diffraction ◽  
Charge Ordering ◽  
High Flux ◽  
Charge Redistribution ◽  
Structural Rearrangements

Neutron powder diffraction allows the rapid determination of the charge redistribution and structural rearrangements as, and after, a material undergoes long range charge-ordering.

Sign in / Sign up

Export Citation Format

Share Document