In Situ Ultralow-Frequency Raman Tracking of the Polymorphic Transformation of Crystalline 1,1′-Binaphthyl

2014 ◽  
Vol 118 (5) ◽  
pp. 2702-2709 ◽  
Author(s):  
Chun-Fu Chang ◽  
Szu-Cheng Wang ◽  
Shinsuke Shigeto
Keyword(s):  
Polymorphic Transformation ◽  
Ultralow Frequency

scholarly journals Imaging the Polymorphic Transformation in a Single Cu6Sn5 Grain in a Solder Joint

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2229 ◽  
Author(s):  
Flora Somidin ◽  
Hiroshi Maeno ◽  
Xuan Tran ◽  
Stuart D. McDonald ◽  
Mohd Mohd Salleh ◽  
...  
Keyword(s):  
Solder Joint ◽  
Polymorphic Transformation ◽  
Structural Evolution ◽  
Real Space ◽  
Transformation Behavior ◽  
New Approach ◽  
Transmission Electron ◽  
Contrast Pattern ◽  
In Situ Observations

In-situ observations of the polymorphic transformation in a single targeted Cu6Sn5 grain constrained between Sn-0.7 wt % Cu solder and Cu-Cu3Sn phases and the associated structural evolution during a solid-state thermal cycle were achieved via a high-voltage transmission electron microscope (HV-TEM) technique. Here, we show that the monoclinic η′-Cu6Sn5 superlattice reflections appear in the hexagonal η-Cu6Sn5 diffraction pattern upon cooling to isothermal 140 °C from 210 °C. The in-situ real space imaging shows that the η′-Cu6Sn5 contrast pattern is initiated at the grain boundary. This method demonstrates a new approach for further understanding the polymorphic transformation behavior on a real solder joint.

Direct observation of α- to β-glycine transformation during the ionic liquid-mediated crystallization process

CrystEngComm ◽  
2018 ◽  
Vol 20 (19) ◽  
pp. 2705-2712
Author(s):  
Liangfei Ouyang ◽  
Tengfei Zheng ◽  
Liang Shen
Keyword(s):  
Ionic Liquid ◽  
Direct Observation ◽  
Liquid Water ◽  
Polymorphic Transformation ◽  
Crystallization Process ◽  
Water System ◽  
X Ray Diffraction ◽  
X Ray

The application of in situ powder X-ray diffraction (XRD) to monitor the polymorphic transformation and crystallization of glycine from an ionic liquid–water system is introduced.

In situsynchrotron powder diffraction study of active belite clinkers

2007 ◽  
Vol 40 (6) ◽  
pp. 999-1007 ◽  
Author(s):  
Ángeles G. De la Torre ◽  
Khadija Morsli ◽  
Mohammed Zahir ◽  
Miguel A.G. Aranda
Keyword(s):  
High Temperature ◽  
High Resolution ◽  
Powder Diffraction ◽  
Polymorphic Transformation ◽  
High Energy ◽  
Dicalcium Silicate ◽  
Polymorphic Transformations ◽  
X Ray ◽  
High Temperature Reactions

The clinkerization processes to form belite clinkers, with theoretical compositions close to 60 wt% of Ca2SiO4, have been studiedin situby high-resolution high-energy (λ = 0.30 Å) synchrotron X-ray powder diffraction. In order to obtain active belite cements, different amounts of K2O, Na2O and SO3have been added. The existence range of the high-temperature phases has been established and, furthermore, Rietveld quantitative phase analyses at high temperature have been performed for all patterns. The following high-temperature reactions have been investigated: (i) polymorphic transformations of dicalcium silicate, \alpha_{\rm L}'-Ca2SiO4↔ \alpha_{\rm H}'-Ca2SiO4from 1170 to 1230 K, and \alpha_{\rm H}'-Ca2SiO4↔ α-Ca2SiO4from 1500 to 1600 K; (ii) melting of the aluminates phases, Ca3Al2O6and Ca4(Al2Fe2)O10, above ∼1570 K; and (iii) reaction of Ca2SiO4with CaO to yield Ca3SiO5above ∼1550 K. Moreover, in all the studied compositions the temperature of the polymorphic transformation \alpha_{\rm H}'-Ca2SiO4↔ α-Ca2SiO4has decreased with the addition of activators. Finally, active belite clinkers were produced as the final samples contained α-belite phases.

Monitoring the Polymorphic Transformation of Imidacloprid Using in Situ FBRM and PVM

2013 ◽  
Vol 17 (3) ◽  
pp. 375-381 ◽  
Author(s):  
Jing Zhao ◽  
Mingliang Wang ◽  
Baoli Dong ◽  
Qi Feng ◽  
Chunxiang Xu
Keyword(s):  
Polymorphic Transformation

Kinetics and Mechanism of the C49 to C54 Titanium Disilicide Polymorphic Transformation

1993 ◽  
Vol 320 ◽  
Author(s):  
Z. Ma ◽  
G. Ramanath ◽  
L.H. Allen
Keyword(s):  
Polymorphic Transformation ◽  
Structural Transition ◽  
Structural Characteristics ◽  
Kinetics And Mechanism ◽  
Orientation Relationships ◽  
Titanium Disilicide ◽  
Transmission Electron ◽  
Interphase Boundaries ◽  
Two Phases

ABSTRACTThe kinetics and mechanism of the C49 to C54 TiSi2 polymorphic transformation have been investigated in a temperature range from 660 to 720°C using in situ sheet resistance measurement and transmission electron microscopy. The kinetics results were correlated with the microstructural changes during the phase transformation. The main structural characteristics demonstrating the mechanism of the transformation were established by examining the nucleation and growth of the C54-TiSi2 in the polycrystalline C49-TiSi2 thin films. It was found that the C54 nuclei predominantly formed at grain edges (three-grain junctions) of the C49 phase and grew very fast by moving its incoherent interphase boundaries. Preliminary results have not revealed rigorous orientation relationships between the two phases. It is suggested that the C49 to C54 structural transition is massive in nature.

In situ AFM observation of polymorphic transformation at crystal surface of glycine

2005 ◽  
Vol 275 (1-2) ◽  
pp. e1691-e1695 ◽  
Author(s):  
Akihiko Ito ◽  
Maiko Yamanobe-Hada ◽  
Hitoshi Shindo
Keyword(s):  
Polymorphic Transformation ◽  
Crystal Surface ◽  
Afm Observation

Imaging molecular crystal polymorphs and their polycrystalline microstructures in situ by ultralow-frequency Raman spectroscopy

2014 ◽  
Vol 50 (85) ◽  
pp. 12973-12976 ◽  
Author(s):  
Chun-Fu Chang ◽  
Hajime Okajima ◽  
Hiro-o Hamaguchi ◽  
Shinsuke Shigeto
Keyword(s):  
Raman Spectroscopy ◽  
Molecular Crystal ◽  
Ultralow Frequency
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