The influence of crystal structure and formation path of precursor on phosphate adsorption during oxidation-hydrolysis phase transition of siderite

2021 ◽  
pp. 133358
Author(s):  
Bobo Xing ◽  
Binghao Zhao ◽  
Mengjie Liu ◽  
Nigel J. D. Graham ◽  
Wenzheng Yu
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Phosphate Adsorption

Dynamic low-dose electron diffraction and imaging of phase transitions in polymers

1993 ◽  
Vol 51 ◽  
pp. 890-891
Author(s):  
David C. Martin ◽  
Jun Liao
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Electron Diffraction ◽  
Low Dose ◽  
Dark Field ◽  
Continuous Change ◽  
Selected Area Electron Diffraction ◽  
Resolution Electron ◽  
Chain Axis ◽  
High Resolution Electron Micrographs

By careful control of the electron beam it is possible to simultaneously induce and observe the phase transformation from monomer to polymer in certain solid-state polymcrizable diacetylenes. The continuous change in the crystal structure from DCHD diacetylene monomer (a=1.76 nm, b=1.36 nm, c=0.455 nm, γ=94 degrees, P2l/c) to polymer (a=1.74 nm, b=1.29 nm, c=0.49 nm, γ=108 degrees, P2l/c) occurs at a characteristic dose (10−4C/cm2) which is five orders of magnitude smaller than the critical end point dose (20 C/cm2). Previously we discussed the progress of this phase transition primarily as observed down the [001] zone (the chain axis direction). Here we report on the associated changes of the dark field (DF) images and selected area electron diffraction (SAED) patterns of the crystals as observed from the side (i.e., in the [hk0] zones).High resolution electron micrographs (HREM), DF images, and SAED patterns were obtained on a JEOL 4000 EX HREM operating at 400 kV.

crystal structure and phase transition in the compound [C6H5CH2NH2CH3]10Sb6Cl28

2006 ◽  
Vol 31 (1) ◽  
pp. 39-48
Author(s):  
Najla Vix-Gurtel ◽  
Chaari Dentzer ◽  
Slaheddine Chaabouni ◽  
Jean-Michel Savariault ◽  
Abdelhamid ben Salah
Keyword(s):  
Crystal Structure ◽  
Phase Transition

Ab-initio investigation of crystal structure and pressure induced phase transition in ThO2 and PuO2

2021 ◽  
pp. 102579
Author(s):  
Shilpa Singh ◽  
Yogesh Sonvane ◽  
K.A. Nekrasov ◽  
A.S. Boyarchenkov ◽  
A. Ya. Kupryazhkin ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Ab Initio

scholarly journals Temperature Dependence of Electrical Properties and Crystal Structure of 0.29Pb(In1/2Nb1/2)O3–0.44Pb(Mg1/3Nb2/3)O3–0.27PbTiO3Single Crystals

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Qian Li ◽  
Yun Liu ◽  
Andrew Studer ◽  
Zhenrong Li ◽  
Ray Withers ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Electrical Properties ◽  
Dielectric Permittivity ◽  
Neutron Diffraction ◽  
Electrical Measurement ◽  
Temperature Dependent ◽  
Electromechanical Properties ◽  
Polar Order

We characterized the temperature dependent (~25–200°C) electromechanical properties and crystal structure of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3single crystals usingin situelectrical measurement and neutron diffraction techniques. The results show that the poled crystal experiences an addition phase transition around 120°C whereas such a transition is absent in the unpoled crystal. It is also found that the polar order persists above the maximum dielectric permittivity temperature at which the crystal shows a well-defined antiferroelectric behavior. The changes in the electrical properties and underlying crystal structure are discussed in the paper.

NQR and Crystal Structure of 4,5-Dichloroimidazole, C3H2N2Cl2

1992 ◽  
Vol 47 (1-2) ◽  
pp. 177-181 ◽  
Author(s):  
Shi-Qi Dou ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Temperature Dependence ◽  
Room Temperature ◽  
Unit Cell ◽  
Space Group ◽  
Temperature Range ◽  
Temperature Coefficients ◽  
Group D

AbstractThe two line 35Cl NQR spectrum of 4,5-dichloroimidazole was measured in the temperature range 77≦ T/K ≦ 389. The temperature dependence of the NQR frequencies conforms with the Bayer model and no phase transition is indicated in the curves v ( 35Cl)= f(T). Also the temperature coefficients of the 35Cl NQR frequencies are "normal". At 77 K the 35Cl NQR frequencies are 37.409 MHz and 36.172 MHz and at 389 K 35.758 MHz and 34.565 MHz. The compound crystallizes at room temperature with the tetragonal space group D44-P41212, Z = 8 molecules per unit cell; at 295 K : a = 684.2(5) pm, c = 2414.0(20) pm. The relations between the crystal structure and the NQR spectrum are discussed.

NQR, NMR, and X-ray crystal structure studies of [4-C2H5-C6H4NH3]2MBr4 (M=Zn, Cd)

2018 ◽  
Vol 73 (9) ◽  
pp. 611-616
Author(s):  
Hideta Ishihara ◽  
Hisashi Honda ◽  
Ingrid Svoboda ◽  
Hartmut Fuess
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Temperature Dependence ◽  
Benzene Ring ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Unit Cell ◽  
Organic Layers ◽  
Nuclear Magnetic Resonance Spectra ◽  
Quadrupole Resonance

AbstractThe crystal structure of [4-C2H5-C6H4NH3]2ZnBr4 (1) has been determined at 150(2) K: triclinic, P1̅, a=724.82(2), b=1194.20(4), c=1322.26(4) pm, α=74.151(3), β=80.887(3), γ=80.434(3)°, and Z=2. There are two crystallographically independent cations in the unit cell of 1: one has its benzene ring perpendicular to the crystallographic a axis of the unit cell and the other one has its benzene ring perpendicular to the c axis. These cations are alternatingly located along the c axis and form organic layers, and the ZnBr4 anions form inorganic layers in between. Zn–Br···H–N hydrogen bonds are formed between cations and anions. In accordance with the crystal structure, four nuclear quadrupole resonance (NQR) lines of 81Br were observed. The temperature dependence of the 81Br NQR frequencies between 77 and 320 K shows a peculiar feature which is not due to a structural phase transition. The measurement of 13C nuclear magnetic resonance spectra at around T=340 K indicates a redistribution of cations. The temperature dependence of 81Br NQR frequencies and differential thermal analysis measurements show that [4-C2H5-C6H4NH3]2CdBr4 (2) undergoes a structural phase transition at around 190 K.

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