Temperature dependence of crystal structure of CaGeO3high-pressure perovskite phase and experimental determination of its Debye temperatures studied by low- and high-temperature single-crystal X-ray diffraction

2015 ◽  
Vol 100 (5-6) ◽  
pp. 1190-1202 ◽  
Author(s):  
Akihiko Nakatsuka ◽  
Shoichi Kuribayashi ◽  
Noriaki Nakayama ◽  
Hiroshi Fukui ◽  
Hiroshi Arima ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Single Crystal ◽  
Temperature Dependence ◽  
Experimental Determination ◽  
Perovskite Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Debye Temperatures

scholarly journals Magnetically Oriented Powder Crystal to Indexing and Structure Determination

2014 ◽  
Vol 70 (a1) ◽  
pp. C1560-C1560
Author(s):  
Fumiko Kimura ◽  
Wataru Oshima ◽  
Hiroko Matsumoto ◽  
Hidehiro Uekusa ◽  
Kazuaki Aburaya ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Lattice ◽  
Powder Diffraction ◽  
Diffraction Method ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Lattice Parameters

In pharmaceutical sciences, the crystal structure is of primary importance because it influences drug efficacy. Due to difficulties of growing a large single crystal suitable for the single crystal X-ray diffraction analysis, powder diffraction method is widely used. In powder method, two-dimensional diffraction information is projected onto one dimension, which impairs the accuracy of the resulting crystal structure. To overcome this problem, we recently proposed a novel method of fabricating a magnetically oriented microcrystal array (MOMA), a composite in which microcrystals are aligned three-dimensionally in a polymer matrix. The X-ray diffraction of the MOMA is equivalent to that of the corresponding large single crystal, enabling the determination of the crystal lattice parameters and crystal structure of the embedded microcrytals.[1-3] Because we make use of the diamagnetic anisotropy of crystal, those crystals that exhibit small magnetic anisotropy do not take sufficient three-dimensional alignment. However, even for these crystals that only align uniaxially, the determination of the crystal lattice parameters can be easily made compared with the determination by powder diffraction pattern. Once these parameters are determined, crystal structure can be determined by X-ray powder diffraction method. In this paper, we demonstrate possibility of the MOMA method to assist the structure analysis through X-ray powder and single crystal diffraction methods. We applied the MOMA method to various microcrystalline powders including L-alanine, 1,3,5-triphenyl benzene, and cellobiose. The obtained MOMAs exhibited well-resolved diffraction spots, and we succeeded in determination of the crystal lattice parameters and crystal structure analysis.

scholarly journals Rubidium tetrafluoridobromate(III): redetermination of the crystal structure from single-crystal X-ray diffraction data

IUCrData ◽  
2019 ◽  
Vol 4 (11) ◽  
Author(s):  
Artem V. Malin ◽  
Sergei I. Ivlev ◽  
Roman V. Ostvald ◽  
Florian Kraus
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
Diffraction Data ◽  
Structure Type ◽  
X Ray Diffraction ◽  
X Ray ◽  
Square Planar ◽  
Atomic Coordinates

Single crystals of rubidium tetrafluoridobromate(III), RbBrF4, were grown by melting and recrystallizing RbBrF4 from its melt. This is the first determination of the crystal structure of RbBrF4 using single-crystal X-ray diffraction data. We confirmed that the structure contains square-planar [BrF4]− anions and rubidium cations that are coordinated by F atoms in a square-antiprismatic manner. The compound crystallizes in the KBrF4 structure type. Atomic coordinates and bond lengths and angles were determined with higher precision than in a previous report based on powder X-ray diffraction data [Ivlev et al. (2015). Z. Anorg. Allg. Chem. 641, 2593–2598].

Crystal structure determination of Ag2Ga by single crystal X-ray diffraction

1998 ◽  
Vol 213 (12) ◽  
Author(s):  
A. E. Gunnæs ◽  
A. Olsen ◽  
P. T. Zagierski ◽  
B. Klewe ◽  
O. B. Karlsen ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Structure Determination ◽  
Crystal Structure Determination ◽  
X Ray Diffraction ◽  
X Ray

AbstractThe crystal structure of

Investigation into the Crystal Structure of the Perovskite Lead Hafnate, PbHfO3

1998 ◽  
Vol 54 (1) ◽  
pp. 18-28 ◽  
Author(s):  
D. L. Corker ◽  
A. M. Glazer ◽  
W. Kaminsky ◽  
R. W. Whatmore ◽  
J. Dec ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Room Temperature ◽  
Lead Zirconate ◽  
Crystal Structure Analysis ◽  
Temperature Structure ◽  
X Ray Diffraction ◽  
Neutron Data ◽  
X Ray

The room-temperature crystal structure of the perovskite lead hafnate PbHfO3 is investigated using both low-temperature single crystal X-ray diffraction (Mo Kα radiation, λ = 0.71069 Å) and polycrystalline neutron diffraction (D1A instrument, ILL, λ = 1.90788 Å). Single crystal X-ray data at 100 K: space group Pbam, a = 5.856 (1), b = 11.729 (3), c = 8.212 (2) Å, V = 564.04 Å3 with Z = 8, μ = 97.2 mm−1, F(000) = 1424, final R = 0.038, wR = 0.045 over 439 reflections with F >1.4σ(F). Polycrystalline neutron data at 383 K: a = 5.8582 (3), b = 11.7224 (5), c = 8.2246 (3) Å, V = 564.80 Å3 with χ2 = 1.62. Although lead hafnate has been thought to be isostructural with lead zirconate, no complete structure determination has been reported, as crystal structure analysis in both these materials is not straightforward. One of the main difficulties encountered is the determination of the oxygen positions, as necessary information lies in extremely weak l = 2n + 1 X-ray reflections. To maximize the intensity of these reflections the X-ray data are collected at 100 K with unusually long scans, a procedure which had previously been found successful with lead zirconate. In order to establish that no phase transitions exist between room temperature and 100 K, and hence that the collected X-ray data are relevant to the room-temperature structure, birefringence measurements for both PbZrO3 and PbHfO3 are also reported.

High-temperature, high-pressure hydrothermal synthesis, crystal structure and photoluminescent properties, of K3[Gd1−xTbxGe3O8(OH)2] (x = 0, 0.3, 0.1, 1)

RSC Advances ◽  
2014 ◽  
Vol 4 (51) ◽  
pp. 26951-26955 ◽  
Author(s):  
Wei Liu ◽  
Min Yang ◽  
Ying Ji ◽  
Fuyang Liu ◽  
Ying Wang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
Hydrothermal Synthesis ◽  
Single Crystal ◽  
Hydrothermal Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Temperature High Pressure

A family of new lanthanide germanates K3LnGe3O8(OH)2 have been synthesized by a high-temperature, high-pressure hydrothermal method and characterized by single-crystal X-ray diffraction.

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