Picosecond ultrasonics and transient thermoreflectance methods for characterization of grain boundary microstructure and thermal transport (Conference Presentation)

2018 ◽  
Author(s):  
Marat Khafizov ◽  
David H. Hurley
Keyword(s):  
Grain Boundary ◽  
Thermal Transport ◽  
Boundary Microstructure ◽  
Picosecond Ultrasonics

Characterization of intergranular cuprous oxide in polycrystalline YBa2Cu3O7-x

1988 ◽  
Vol 46 ◽  
pp. 880-881
Author(s):  
Bradley L. Thiel ◽  
Chan Han R. P. ◽  
Kurosky L. C. Hutter ◽  
I. A. Aksay ◽  
Mehmet Sarikaya
Keyword(s):  
Grain Boundary ◽  
Cuprous Oxide ◽  
Room Temperature ◽  
Boundary Phase ◽  
Spectroscopic Techniques ◽  
Transition Width ◽  
Practical Applications ◽  
Thin Foils ◽  
Superconducting Oxides

The identification of extraneous phases is important in understanding of high Tc superconducting oxides. The spectroscopic techniques commonly used in determining the origin of superconductivity (such as RAMAN, XPS, AES, and EXAFS) are surface-sensitive. Hence a grain boundary phase several nanometers thick could produce irrelevant spectroscopic results and cause erroneous conclusions. The intergranular phases present a major technological consideration for practical applications. In this communication we report the identification of a Cu2O grain boundary phase which forms during the sintering of YBa2Cu3O7-x (1:2:3 compound).Samples are prepared using a mixture of Y2O3. CuO, and BaO2 powders dispersed in ethanol for complete mixing. The pellets pressed at 20,000 psi are heated to 950°C at a rate of 5°C per min, held for 1 hr, and cooled at 1°C per min to room temperature. The samples show a Tc of 91K with a transition width of 2K. In order to prevent damage, a low temperature stage is used in milling to prepare thin foils which are then observed, using a liquid nitrogen holder, in a Philips 430T at 300 kV.

Structural analysis of a Σ5 grain boundary in YBa2Cu3O7δ

1993 ◽  
Vol 51 ◽  
pp. 942-943
Author(s):  
J.-Y. Wang ◽  
Y. Zhu ◽  
A.H. King ◽  
M. Suenaga
Keyword(s):  
Grain Boundary ◽  
Lattice Mismatch ◽  
Weak Link ◽  
Coincidence Site Lattice ◽  
Large Angle ◽  
Dislocation Core ◽  
Superconducting Order Parameter ◽  
Outstanding Problem ◽  
Transmission Electron

One outstanding problem in YBa2Cu3O7−δ superconductors is the weak link behavior of grain boundaries, especially boundaries with a large-angle misorientation. Increasing evidence shows that lattice mismatch at the boundaries contributes to variations in oxygen and cation concentrations at the boundaries, while the strain field surrounding a dislocation core at the boundary suppresses the superconducting order parameter. Thus, understanding the structure of the grain boundary and the grain boundary dislocations (which describe the topology of the boundary) is essential in elucidating the superconducting characteristics of boundaries. Here, we discuss our study of the structure of a Σ5 grain boundary by transmission electron microscopy. The characterization of the structure of the boundary was based on the coincidence site lattice (CSL) model.Fig.l shows two-beam images of the grain boundary near the projection. An array of grain boundary dislocations, with spacings of about 30nm, is clearly visible in Fig. 1(a), but invisible in Fig. 1(b).

Characterization of Thermal Transport in Carbon Nanotube Yarns

2014 ◽  
Author(s):  
Jianli Wang ◽  
Sisi He ◽  
Jiajian Bao ◽  
Xing Zhang ◽  
Juekuan Yang ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Thermal Transport ◽  
Carbon Nanotube Yarns

scholarly journals Picosecond ultrasonics for elasticity-based imaging and characterization of biological cells

2020 ◽  
Vol 128 (16) ◽  
pp. 160902 ◽  
Author(s):  
Fernando Pérez-Cota ◽  
Rafael Fuentes-Domínguez ◽  
Salvatore La Cavera ◽  
William Hardiman ◽  
Mengting Yao ◽  
...  
Keyword(s):  
Biological Cells ◽  
Picosecond Ultrasonics

Atom probe crystallography: Characterization of grain boundary orientation relationships in nanocrystalline aluminium

2011 ◽  
Vol 111 (6) ◽  
pp. 493-499 ◽  
Author(s):  
Michael P. Moody ◽  
Fengzai Tang ◽  
Baptiste Gault ◽  
Simon P. Ringer ◽  
Julie M. Cairney
Keyword(s):  
Grain Boundary ◽  
Atom Probe ◽  
Orientation Relationships ◽  
Boundary Orientation

Characterization of grain boundary disconnections in SrTiO3 part I: the dislocation component of grain boundary disconnections

2018 ◽  
Vol 54 (5) ◽  
pp. 3694-3709 ◽  
Author(s):  
Hadas Sternlicht ◽  
Wolfgang Rheinheimer ◽  
Rafal E. Dunin-Borkowski ◽  
Michael J. Hoffmann ◽  
Wayne D. Kaplan
Keyword(s):  
Grain Boundary

Observation of Growth Front on the Initial Stage of Goss Abnormally-Growing Grain in Fe-3%Si Steel

2013 ◽  
Vol 753 ◽  
pp. 307-310
Author(s):  
Kyung Jun Ko ◽  
Jong Tae Park ◽  
Chan Hee Han
Keyword(s):  
Solid State ◽  
Grain Boundary ◽  
Three Dimensional ◽  
Secondary Recrystallization ◽  
Growth Front ◽  
Very High Frequency ◽  
Grain Boundary Mobility ◽  
Initial Stage ◽  
The Matrix

During abnormal grain growth, a few Goss grains grow exclusively fast and consume the matrix grains. The Goss abnormally-growing grain (AGG) has peculiar features which are irregular grain boundaries and very high frequency of peninsular grains nearby the growth front of AGG and island grains trapped inside AGG. These features might provide a clue for clarifying the mechanism of Goss AGG. The experimentally-observed microstructural feature and grain boundary characterization of Goss were approached by the solid-state wetting mechanism. In this study, observing the three-dimensional wetting morphology in serial section images of Goss AGG by EBSD, we report some direct microstrucrual evidence supporting solid-state wetting mechanism for Goss AGG. The solid-state wetting mechanism for the evolution of the Goss AGG in Fe-3%Si steel explains the microstructural features evolved during secondary recrystallization, which cannot be approached by the conventional theories based on the grain boundary mobility.

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