Phase transition kinetics of LiNi0.5Mn1.5O4 analyzed by temperature-controlled operando X-ray absorption spectroscopy

2016 ◽  
Vol 18 (3) ◽  
pp. 1897-1904 ◽  
Author(s):  
Ikuma Takahashi ◽  
Hajime Arai ◽  
Haruno Murayama ◽  
Kenji Sato ◽  
Hideyuki Komatsu ◽  
...  
Keyword(s):  
Phase Transition ◽  
Low Temperatures ◽  
Reaction Scheme ◽  
X Ray ◽  
Phase Transition Kinetics ◽  
Temperature Controlled ◽  
High And Low Temperatures ◽  
X Ray Absorption ◽  
Kinetics Of ◽  
Charge Discharge

Charge–discharge reaction scheme of LiNi0.5Mn1.5O4 at high and low temperatures.

scholarly journals Studies on the β → α Phase Transition Kinetics of Ti–3.5Al–5Mo–4V Alloy under Isothermal Conditions by X-ray Diffraction

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 90
Author(s):  
Panpan Ge ◽  
Song Xiang ◽  
Yuanbiao Tan ◽  
Xuanming Ji
Keyword(s):  
Phase Transition ◽  
Aging Time ◽  
Solution Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Α Phase ◽  
Precipitate Fraction ◽  
Transformation Mechanisms ◽  
Phase Transition Kinetics ◽  
Kinetics Of

The β → α phase transition kinetics of the Ti–3.5Al–5Mo–4V alloy with two different grain sizes was investigated at the isothermal temperature of 500 °C. A method to estimate the function of the precipitate fraction of the α phase with different aging times was developed based on X-ray diffraction analysis. The value of the α precipitate fraction increased sharply at first, then increased slowly with the aging time, and finally reached equilibrium. The value of the α precipitate fraction was higher in the alloy aged for the same time at a higher solution temperature, while the size of the α precipitate was smaller at a higher solution temperature. The β → α phase transition kinetics under isothermal conditions were modeled in the theoretical frame of the Johnson–Mehl–Avrami–Kolmogorov (JMAK) theory. The kinetic parameters of JMAK deduced different transformation mechanisms. The mechanism of the phase transition in the first stage was dominated by mixed transformation mechanisms (homogeneously nucleated and acicular-grown α structure, and grain boundary-nucleated and grown α precipitate), while the second stage was the growth of the fine α precipitate, which was controlled by slow diffusion. As the aging time increased, the hardness of the Ti–3.5Al–5Mo–4V alloy increased sharply. After the hardness of the alloy reached a plateau, it began to decline. The hardness of the alloy was always higher at a higher solution temperature.

Temperature Effect on the Two-Dimensional Phase Transition Kinetics of Adenine Adsorbed at the Hg Electrode/Aqueous Solution Interface

2003 ◽  
Vol 68 (8) ◽  
pp. 1407-1419 ◽  
Author(s):  
Claudio Fontanesi ◽  
Roberto Andreoli ◽  
Luca Benedetti ◽  
Roberto Giovanardi ◽  
Paolo Ferrarini
Keyword(s):  
Phase Transition ◽  
Aqueous Solution ◽  
Phase Change ◽  
Temperature Effect ◽  
Transition Rate ◽  
Effect Of Temperature ◽  
Two Dimensional ◽  
Solution Interface ◽  
Phase Transition Kinetics ◽  
Kinetics Of

The kinetics of the liquid-like → solid-like 2D phase transition of adenine adsorbed at the Hg/aqueous solution interface is studied. Attention is focused on the effect of temperature on the rate of phase change; an increase in temperature is found to cause a decrease of transition rate.

scholarly journals Local dynamics and phase transition in quantum paraelectric SrTiO3studied by TiK-edge x-ray absorption spectroscopy

2016 ◽  
Vol 712 ◽  
pp. 012101 ◽  
Author(s):  
Andris Anspoks ◽  
Janis Timoshenko ◽  
Juris Purans ◽  
Francesco Rocca ◽  
Vladimir Trepakov ◽  
...  
Keyword(s):  
Phase Transition ◽  
Absorption Spectroscopy ◽  
Local Dynamics ◽  
X Ray ◽  
Quantum Paraelectric ◽  
X Ray Absorption

scholarly journals Two-Electron Reaction without Structural Phase Transition in Nanoporous Cathode Material

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Tomoyuki Matsuda ◽  
Yutaka Moritomo
Keyword(s):  
Phase Transition ◽  
Cathode Material ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Discharge Process ◽  
Charge Capacity ◽  
High Charge ◽  
Valence States ◽  
X Ray Absorption ◽  
Charge Discharge

We investigated the charge/discharge properties, valence states, and structural properties of a nanoporous cathode materialLixMn[Fe(CN)6]0.83·3.5H2O. The film-type electrode ofLixMn[Fe(CN)6]0.83·3.5H2Oexhibited a high charge capacity(=128 mAh g-1)and a good cyclability (87% of the initial value after 100 cycles) and is one of the promising candidates for Li-ion battery cathode. X-ray absorption spectra near the Fe and Mn K-edges revealed that the charge/discharge process is a two-electron reaction; that is,MnII–NC–FeII,MnII–NC–FeIII, andMnIII–NC–FeIII. We further found that the crystal structure remains cubic throughout the charge/discharge process. The lattice constant slightly increased during the[FeII(CN)6]4-/[FeIII(CN)6]3-oxidization reaction while decreased during theMnII/MnIIIoxidization reaction. The two-electron reaction without structural phase transition is responsible for the high charge capacity and the good cyclability.

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