On the role of grain boundaries in nanocrystalline γ-Fe2O3 under high pressure

2012 ◽  
Vol 111 (6) ◽  
pp. 063718 ◽  
Author(s):  
Dongmei Zhang ◽  
Yongsheng Zhang ◽  
Yang Gao ◽  
Yonghao Han ◽  
Chunxiao Gao ◽  
...  
Keyword(s):  
High Pressure ◽  
Grain Boundaries

High pressure study of B12As2: Electrical transport behavior and the role of grain boundaries

2015 ◽  
Vol 117 (4) ◽  
pp. 045302 ◽  
Author(s):  
Qinglin Wang ◽  
Cailong Liu ◽  
Boheng Ma ◽  
Yang Gao ◽  
Matthew Fitzpatrick ◽  
...  
Keyword(s):  
High Pressure ◽  
Grain Boundaries ◽  
Electrical Transport ◽  
Transport Behavior ◽  
High Pressure Study

High-pressure dielectric behavior of polycrystalline CaMoO4: The role of grain boundaries

2018 ◽  
Vol 730 ◽  
pp. 1-6 ◽  
Author(s):  
Tianru Qin ◽  
Qinglin Wang ◽  
Donghui Yue ◽  
Wenshu Shen ◽  
Yalan Yan ◽  
...  
Keyword(s):  
High Pressure ◽  
Grain Boundaries ◽  
Dielectric Behavior

Elucidation of block boundaries as the dissolution channels in hydrated cement

1978 ◽  
Vol 36 (1) ◽  
pp. 484-485
Author(s):  
N.V. Belov ◽  
U.I. Papiashwili ◽  
B.E. Yudovich
Keyword(s):  
Liquid Phase ◽  
Grain Boundaries ◽  
Benzoyl Peroxide ◽  
Phase Contrast ◽  
Active Role ◽  
Point Of View ◽  
Hardened Cement ◽  
Hydrated Cement ◽  
Hardened Cement Paste

It has been almost universally adopted that dissolution of solids proceeds with development of uniform, continuous frontiers of reaction.However this point of view is doubtful / 1 /. E.g. we have proved the active role of the block (grain) boundaries in the main phases of cement, these boundaries being the areas of hydrate phases' nucleation / 2 /. It has brought to the supposition that the dissolution frontier of cement particles in water is discrete. It seems also probable that the dissolution proceeds through the channels, which serve both for the liquid phase movement and for the drainage of the incongruant solution products. These channels can be appeared along the block boundaries.In order to demonsrate it, we have offered the method of phase-contrast impregnation of the hardened cement paste with the solution of methyl metacrylahe and benzoyl peroxide. The viscosity of this solution is equal to that of water.

Carbide precipitation and chromium depletion on coherent twin boundaries in deformed 304 stainless steels

1992 ◽  
Vol 50 (2) ◽  
pp. 1216-1217
Author(s):  
A.H. Advani ◽  
L.E. Murr ◽  
D.J. Matlock ◽  
W.W. Fisher ◽  
P.M. Tarin ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Stainless Steels ◽  
Interfacial Free Energy ◽  
Carbide Precipitation ◽  
Twin Boundaries ◽  
Invariant Structure ◽  
Heat Treated ◽  
Constant Structure ◽  
Cr Depletion

Coherent annealing-twin boundaries are constant structure and energy interfaces with an average interfacial free energy of ∼19mJ/m2 versus ∼210 and ∼835mJ/m2 for incoherent twins and “regular” grain boundaries respectively in 304 stainless steels (SS). Due to their low energy, coherent twins form carbides about a factor of 100 slower than grain boundaries, and limited work has also shown differences in Cr-depletion (sensitization) between twin versus grain boundaries. Plastic deformation, may, however, alter the kinetics and thermodynamics of twin-sensitization which is not well understood. The objective of this work was to understand the mechanisms of carbide precipitation and Cr-depletion on coherent twin boundaries in deformed SS. The research is directed toward using this invariant structure and energy interface to understand and model the role of interfacial characteristics on deformation-induced sensitization in SS. Carbides and Cr-depletion were examined on a 20%-strain, 0.051%C-304SS, heat treated to 625°C-4.5h, as described elsewhere.

High Pressure Studies of Quantum Well Emission and Deep Emission in GaInP(ordered)-GaAs Heterostructures

1997 ◽  
Vol 499 ◽  
Author(s):  
S. H. Kwok ◽  
P. Y. Yu ◽  
K. Uchida ◽  
T. Arai
Keyword(s):  
High Pressure ◽  
Quantum Well ◽  
Emission Band ◽  
Excitation Power ◽  
High Excitation ◽  
High Pressure Studies ◽  
Band Alignments ◽  
High Pressure Study

ABSTRACTWe report on a high pressure study of emission from a series of GaInP(ordered)/GaAs heterostructures. A so-called “deep emission” band at 1.46 eV is observed in all our samples. At high excitation power, quantum well emission emerges in only one structure where thin GaP layers are inserted on both sides of the GaAs well. From the pressure dependent emission in this sample we have determined its band alignments. The role of the GaP layers in suppressing the deep emission is elucidated.

Role of dislocations in the bcc-hcp transition under high pressure: A first-principles approach in beryllium

2020 ◽  
Vol 4 (6) ◽  
Author(s):  
Vanessa Riffet ◽  
Bernard Amadon ◽  
Nicolas Bruzy ◽  
Christophe Denoual
Keyword(s):  
High Pressure ◽  
First Principles

Anomalous narrowing of the shape of the structural process in derivatives of trehalose at high pressure. The role of the internal structure

2021 ◽  
pp. 116321
Author(s):  
Dawid Heczko ◽  
Joanna Grelska ◽  
Karolina Jurkiewicz ◽  
Patrycja Spychalska ◽  
Anna Kasprzycka ◽  
...  
Keyword(s):  
High Pressure ◽  
Internal Structure ◽  
Structural Process ◽  
Derivatives Of
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