In-situ TEM Study of Bismuth Nanostructures

2007 ◽  
Vol 1044 ◽  
Author(s):  
Xiaoting Jia ◽  
Vincent Berube ◽  
Shuo Chen ◽  
Bed Poudel ◽  
Son Hyungbin ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
Structural Behavior ◽  
In Situ Tem ◽  
Electrical Measurements ◽  
Dimensionless Figure Of Merit ◽  
Bi Nanoparticles ◽  
Nanostructured Thermoelectric Materials

AbstractNanostructured thermoelectric materials have attracted lots of interest in recent years, due to their enhanced performance determined by their thermoelectric dimensionless figure of merit. However, because of equipment limitations, not much work has been done on combining simultaneous transport measurements and structural characterization on individual nanostructured thermoelectric materials. With an integrated TEM-STM system, we studied the structural behavior and electrical properties of bismuth (Bi) nanobelts and nanoparticles. Results showed that clean Bi nanostructures free of oxides can be produced by in-situ high temperature electro-migration and Joule annealing processes occurring within the electron microscope. Preliminary electrical measurements indicate a conductivity of two orders of magnitude lower for Bi nanoparticles than that for bulk Bi. Such in-situ studies are highly advantageous for studying the semimetal-semiconductor transition and how this transition could enhance thermoelectric properties.

In situ TEM observations of melting in nanosized eutectic Pb-Cd inclusions embedded in Al

1996 ◽  
Vol 54 ◽  
pp. 986-987
Author(s):  
S. Hagège ◽  
U. Dahmen ◽  
E. Johnson ◽  
A. Johansen ◽  
V.S. Tuboltsev
Keyword(s):  
Electron Microscope ◽  
Melt Spinning ◽  
Ternary Alloys ◽  
Solid Matrix ◽  
Eutectic System ◽  
In Situ Tem ◽  
In Situ Observation ◽  
Orientation Relationships ◽  
Transmission Electron

Small particles of a low-melting phase embedded in a solid matrix with a higher melting point offer the possibility of studying the mechanisms of melting and solidification directly by in-situ observation in a transmission electron microscope. Previous studies of Pb, Cd and other low-melting inclusions embedded in an Al matrix have shown well-defined orientation relationships, strongly faceted shapes, and an unusual size-dependent superheating before melting.[e.g. 1,2].In the present study we have examined the shapes and thermal behavior of eutectic Pb-Cd inclusions in Al. Pb and Cd form a simple eutectic system with each other, but both elements are insoluble in solid Al. Ternary alloys of Al (Pb,Cd) were prepared from high purity elements by melt spinning or by sequential ion implantation of the two alloying additions to achieve a total alloying addition of up to lat%. TEM observations were made using a heating stage in a 200kV electron microscope equipped with a video system for recording dynamic behavior.

Investigation of Thermoelectric Materials: Substitution effect of Bi on the Ag1-xPb18MTe20 (M = Sb, Bi) (x = 0, 0.14, 0.3)

2007 ◽  
Vol 1044 ◽  
Author(s):  
Mi-kyung Han ◽  
Huijun Kong ◽  
Ctirad Uher ◽  
Mercouri G Kanatzidis
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Substitution Effect ◽  
Dimensionless Figure Of Merit ◽  
The Matrix ◽  
Mass Fluctuation

AbstractWe performed comparative investigations of the Ag1-xPb18MTe20 (M = Bi, Sb) (x = 0, 0.14, 0.3) system to better understand the roles of Sb and Bi on the thermoelectric properties. In both systems, the electrical conductivity nearly keeps the same values, while the Seebeck coefficient decreases dramatically in going from Sb to Bi. Compared to the lattice thermal conductivity of PbTe, that of AgPb18BiTe20 is substantially reduced. The lattice thermal conductivity of the Bi analog, however, is higher than that of AgPb18SbTe20 and this is attributed largely to the decrease in the degree of mass fluctuation between the nanostructures and the matrix (for the Bi analog). As a result the dimensionless figure of merit ZT of Ag1-xPb18MTe20 (M = Bi) is found to be smaller than that of Ag1-xPb18MTe20 (M = Sb).

scholarly journals Distinguishing Isotopes in the Electron Microscope: In-situ TEM-SIMS Correlative Analysis

2016 ◽  
Vol 22 (S3) ◽  
pp. 222-223
Author(s):  
Lluís Yedra ◽  
Santhana Eswara ◽  
David Dowsett ◽  
Tom Wirtz
Keyword(s):  
Electron Microscope ◽  
In Situ Tem ◽  
Correlative Analysis

Insights into the growth of bismuth nanoparticles on 2D structured BiOCl photocatalysts: an in situ TEM investigation

2015 ◽  
Vol 44 (36) ◽  
pp. 15888-15896 ◽  
Author(s):  
Xiaofeng Chang ◽  
Shuangbao Wang ◽  
Qi Qi ◽  
Mohammed A. Gondal ◽  
Siddique G. Rashid ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
In Situ Tem ◽  
Bismuth Nanoparticles ◽  
Transmission Electron

The formation and growth of bismuth nanoparticles onto BiOCl have been directly observed and characterized using a transmission electron microscope.

In situ TEM studies of NaCl-gas reactions

1978 ◽  
Vol 36 (1) ◽  
pp. 440-441
Author(s):  
T.T. Chung ◽  
J. Dash ◽  
R.J. O'Brien
Keyword(s):  
Thin Film ◽  
Electron Microscope ◽  
Water Vapor ◽  
Atmospheric Aerosols ◽  
In Situ Tem ◽  
Video Tape ◽  
Structure And Morphology ◽  
A Cell ◽  
Gas Reactions

The electron microscope is an important instrument for studying the structure and morphology of particulates collected from the atmosphere, but its potential for direct observation of the interactions between atmospheric aerosols and gases has not been explored previously. A cell with thin film windows and ports to permit the passage of gases was constructed for this purpose, Fig. 1. This cell is designed for use in the tilting stage of a Hitachi HU125 TEM. The thin film windows (manufactured by E. F. Full am, Inc. (1) ) consist of a composite film of formvar and evaporated SiO on 400 mesh Cu grids.In the first experiments with this cell, particles of NaCl were collected from a modified De Vilbiss nebulizer on the lower window of the cell and observed continuously during passage through the cell of either (1) water vapor or (2) water vapor and NO2.The image was recorded continuously on video tape and intermittently on sheet film.

Sign in / Sign up

Export Citation Format

Share Document