Crystal structure, elastic properties and phase transition of triclinic ammonium hydrogen succinate, NH4HC4H4O4

1993 ◽  
Vol 206 (1-2) ◽  
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Elastic Properties ◽  
Ammonium Hydrogen

Crystal structure, elastic properties and phase transition of triclinic ammonium hydrogen succinate, NH4HC4H4O4

1993 ◽  
Vol 206 (2) ◽  
Author(s):  
S. Haussühl ◽  
J. Schreuer
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Aqueous Solutions ◽  
Single Crystals ◽  
Elastic Properties ◽  
Structure Analysis ◽  
Optical Quality ◽  
Space Group ◽  
X Ray ◽  
Ammonium Hydrogen

AbstractLarge optical quality, single crystals of triclinic ammonium hydrogen succinate have been grown from aqueous solutions. An X-ray structure analysis yields space group

Structure of ammonium hydrogen succinate above and below the phase transition around 170K

1996 ◽  
Vol 52 (2) ◽  
pp. 323-327 ◽  
Author(s):  
A. Hirano ◽  
Y. Kubozono ◽  
H. Maeda ◽  
H. Ishida ◽  
S. Kashino
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Hydrogen Bonds ◽  
Order Phase Transition ◽  
Space Group ◽  
X Ray ◽  
Ammonium Hydrogen ◽  
Significant Change ◽  
Short Hydrogen Bonds ◽  
Second Order Phase Transition

For crystals of ammonium hydrogen succinate it is known that the space group is P{\bar 1} with Z = 2 at 293 K and the second-order phase transition occurs around 170 K. X-ray crystal structure analyses above and below 170 K have been carried out in order to study the change in mode of short hydrogen bonds between the hydrogen succinate ions. The space group was determined to be P{\bar 1} at 150 and 190 K by structure analysis. No ordering of the H-atom positions in the short hydrogen bonds occurs by the phase transition. The hydrogen bonds show a decrease in the O...O distances with a decrease in temperature from 290 to 190 K, but no significant change in the geometries between 190 and 150 K. Disorder of the NH4 + ion is not observed at 297, 190 and 150 K. Significant change through the phase transition is found only in the geometry of one of the N—H...O hydrogen bonds between ammonium and hydrogen succinate ions.

Anomalies of Elastic Properties at Phase Transitions in Rare Earth Cobaltites RBaCo4O7 (R = Y, Er - Lu)

2012 ◽  
Vol 190 ◽  
pp. 482-485 ◽  
Author(s):  
Z.A. Kazei ◽  
V.V. Snegirev ◽  
L.P. Kozeeva ◽  
M.Yu. Kameneva
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Rare Earth ◽  
Transition Temperature ◽  
Elastic Properties ◽  
Magnetic Phase ◽  
Structural Phase ◽  
Exchange Interactions ◽  
Temperature Decrease ◽  
Low Dimension

Elastic properties of rare-earth cobaltites RBaCo4O7 (R = Y, Er - Lu) are studied in the temperature range (4.2 - 300) K. Significant softening of Youngs modulus for Lu-and Yb-cobaltites is found at temperature decrease, showing an instability of the crystal structure and accompanying by a reverse jump at the structural phase transition. Softening and jump at phase transition decrease more than by the order of value, while the transition temperature Ts and hysteresis dTs enlarge from Lu-to Tm-and Er-compounds. Smooth and weak elastic anomaly at the magnetic phase transition is found resulting from low dimension and frustration of exchange interactions in the Co subsystem in most of the rare-earth cobaltites studied.

Structure of Ammonium Hydrogen Succinate at 80 and 20 K

1998 ◽  
Vol 54 (6) ◽  
pp. 889-894 ◽  
Author(s):  
S. Kashino ◽  
J. Taka ◽  
T. Yoshida ◽  
Y. Kubozono ◽  
H. Ishida ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Hydrogen Bond ◽  
Structural Change ◽  
Hydrogen Bonds ◽  
Order Phase Transition ◽  
Ammonium Ion ◽  
Ammonium Hydrogen ◽  
Bifurcated Hydrogen Bond ◽  
Second Order Phase Transition

The crystal structure of ammonium hydrogen succinate has been determined at 80 and 20 K in order to clarify the structural change at the second-order phase transition at 170 K. The geometries of all the hydrogen bonds in the structure were analyzed by combining new geometric data with data obtained previously at 297, 190 and 150 K. The O...O distances of two O—H...O hydrogen bonds involving the hydrogen succinate ions increase as the temperature decreases below T c and the N...O distance of a weak bifurcated hydrogen bond involving the ammonium ion decreases below T c . It is noted that the phase transition occurs so that the bifurcated hydrogen bond is retained below T c . There was no evidence of a descent in space group from P1¯ to P1 below T c and the formation of a superstructure below T c was not detected.

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

scholarly journals Elastic Properties and Energy Loss Related to the Disorder–Order Ferroelectric Transitions in Multiferroic Metal–Organic Frameworks [NH4][Mg(HCOO)3] and [(CH3)2NH2][Mg(HCOO)3]

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3125
Author(s):  
Zhiying Zhang ◽  
Hongliang Yu ◽  
Xin Shen ◽  
Lei Sun ◽  
Shumin Yue ◽  
...  
Keyword(s):  
Phase Transition ◽  
Energy Loss ◽  
Elastic Properties ◽  
Ferroelectric Phase ◽  
Loss Modulus ◽  
Structural Phase ◽  
Metal Organic Frameworks ◽  
First Order ◽  
Metal Organic ◽  
Elastic Anomalies

Elastic properties are important mechanical properties which are dependent on the structure, and the coupling of ferroelasticity with ferroelectricity and ferromagnetism is vital for the development of multiferroic metal–organic frameworks (MOFs). The elastic properties and energy loss related to the disorder–order ferroelectric transition in [NH4][Mg(HCOO)3] and [(CH3)2NH2][Mg(HCOO)3] were investigated using differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The DSC curves of [NH4][Mg(HCOO)3] and [(CH3)2NH2][Mg(HCOO)3] exhibited anomalies near 256 K and 264 K, respectively. The DMA results illustrated the minimum in the storage modulus and normalized storage modulus, and the maximum in the loss modulus, normalized loss modulus and loss factor near the ferroelectric transition temperatures of 256 K and 264 K, respectively. Much narrower peaks of loss modulus, normalized loss modulus and loss factor were observed in [(CH3)2NH2][Mg(HCOO)3] with the peak temperature independent of frequency, and the peak height was smaller at a higher frequency, indicating the features of first-order transition. Elastic anomalies and energy loss in [NH4][Mg(HCOO)3] near 256 K are due to the second-order paraelectric to ferroelectric phase transition triggered by the disorder–order transition of the ammonium cations and their displacement within the framework channels, accompanied by the structural phase transition from the non-polar hexagonal P6322 to polar hexagonal P63. Elastic anomalies and energy loss in [(CH3)2NH2][Mg(HCOO)3] near 264 K are due to the first-order paraelectric to ferroelectric phase transitions triggered by the disorder–order transitions of alkylammonium cations located in the framework cavities, accompanied by the structural phase transition from rhombohedral R3¯c to monoclinic Cc. The elastic anomalies in [NH4][Mg(HCOO)3] and [(CH3)2NH2][Mg(HCOO)3] showed strong coupling of ferroelasticity with ferroelectricity.

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