scholarly journals Temperature Calibration forIn SituEnvironmental Transmission Electron Microscopy Experiments

2015 ◽  
Vol 21 (6) ◽  
pp. 1622-1628 ◽  
Author(s):  
Jonathan P. Winterstein ◽  
Pin Ann Lin ◽  
Renu Sharma
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Elevated Temperatures ◽  
Lattice Parameter ◽  
Hydrogen Gas ◽  
Material Behavior ◽  
Sample Temperature ◽  
Transmission Electron ◽  
Local Sample

AbstractIn situenvironmental transmission electron microscopy (ETEM) experiments require specimen heating holders to study material behavior in gaseous environments at elevated temperatures. In order to extract meaningful kinetic parameters, such as activation energies, it is essential to have a direct and accurate measurement of local sample temperature. This is particularly important if the sample temperature might fluctuate, for example when room temperature gases are introduced to the sample area. Using selected-area diffraction (SAD) in an ETEM, the lattice parameter of Ag nanoparticles was measured as a function of the temperature and pressure of hydrogen gas to provide a calibration of the local sample temperature. SAD permits measurement of temperature to an accuracy of ±30°C using Ag lattice expansion. Gas introduction can cause sample cooling of several hundred degrees celsius for gas pressures achievable in the ETEM.

scholarly journals In-situ Transmission Electron Microscopy at pressures above 1 bar and elevated temperatures

2012 ◽  
Vol 18 (S2) ◽  
pp. 1114-1115 ◽  
Author(s):  
H. Zandbergen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Elevated Temperatures ◽  
Transmission Electron

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

In-Situ High Resolution Transmission Electron Microscopy of Dynamic Events During the Amorphous to Crystalline Phase Transformation in Silicon

1985 ◽  
Vol 62 ◽  
Author(s):  
M. A. Parker ◽  
T. W. Sigmon ◽  
R. Sinclair
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phase Transformation ◽  
Solid State ◽  
High Resolution ◽  
Elevated Temperatures ◽  
Video Recording ◽  
Dynamic Events ◽  
Transmission Electron

ABSTRACTA technique has been developed which employs high resolution transmission electron microscopy (HRTEM) for the observation of the atomic mechanisms associated with solid state phase transformation as they occur at elevated temperatures. It consists of the annealing in-situ of cross-section transmission electron microscopy (TEM) specimens that have been favorably oriented for lattice fringe imaging and the video-recording of dynamic events as they occur in real-time. By means of this technique, we report the first video-recorded lattice images of crystallographic defect motion in silicon, viz. the motion of dislocations and stacking faults, as well as the first such images of the atomic mechanisms responsible for the amorphous to crystalline (a-c) phase transformation, viz. heterogeneous nucleation of crystal nuclei, coalescence of crystal nuclei by co-operative atomic processes, ledge motion at the growth interface, and normal growth in silicon. This technique holds great potential for the elucidation of the atomic mechanisms involved in reaction kinetics in the solid state.

An Environmental Transmission Electron Microscope for in situ Synthesis and Characterization of Nanomaterials

2005 ◽  
Vol 20 (7) ◽  
pp. 1695-1707 ◽  
Author(s):  
Renu Sharma
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Elevated Temperatures ◽  
Dark Field ◽  
In Situ Synthesis ◽  
Synthesis And Characterization ◽  
Transmission Electron ◽  
Electron Microscopes

The world of nanomaterials has become the real world for most applications in the area of nanotechnology. As postsynthesis handling of materials at the nanoscale level is impractical, nanomaterials must be synthesized directly as part of a device or circuit. The demands of nanotechnology have led to modifications in the design of transmission electron microscopes (TEMs) that enable in situ synthesis and characterization simultaneously. The environmental TEM (ETEM) is one such modified instrument that has often been used to follow gas–solid and/or liquid–solid interactions at elevated temperatures. Although the history and development of the ETEM, also called the controlled atmosphere or environmental cell TEM, is as old as transmission electron microscopy itself, developments in the design of medium-voltage TEMs have succeeded in bringing resolutions down to the subnanometer level. A modern ETEM equipped with a field-emission gun, energy filter or electron energy-loss spectrometer, scanning transmission electron microscopy coils, and bright-field and dark-field detectors can be a versatile tool for understanding chemical processes at the nanometer level. This article reviews the design and operations of a dedicated ETEM. Its applications range from the in situ characterization of reaction steps, such as oxidation-reduction and hydroxylation, to the in situ synthesis of nanomaterials, such as quantum dots and carbon nanotubes. Some examples of the current and the future applications for the synthesis and characterization of nanomaterials are also discussed.

Ionization-induced effects in amorphous apatite at elevated temperatures

2008 ◽  
Vol 23 (4) ◽  
pp. 962-967 ◽  
Author(s):  
In-Tae Bae ◽  
Yanwen Zhang ◽  
William J. Weber ◽  
Manabu Ishimaru ◽  
Yoshihiko Hirotsu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Beam ◽  
Elevated Temperatures ◽  
Amorphous Material ◽  
Transmission Electron ◽  
Oxygen Migration ◽  
Structural Contrast

Electron-beam-induced effects in preamorphized Sr2Nd8(SiO4)6O2 were investigated in situ using transmission electron microscopy with 200-keV electrons at temperatures ranging from 380 to 780 K. Within the electron-irradiated area, epitaxial recrystallization was observed from the amorphous/crystalline interface toward the surface, with the rate of recrystallization increasing as temperature increased from 380 to 580 K. Structural contrast features (i.e., O deficient amorphous material), as well as recrystallization, were observed outside of the irradiation area at temperatures from 680 to 780 K. Ionization-induced processes and local nonstoichiometry induced by oxygen migration and desorption are possible mechanisms for the electron-beam- induced recrystallization and for the formation of the structural contrast features, respectively.

In situ transmission electron microscopy of nano-sized metal clusters

2004 ◽  
Vol 839 ◽  
Author(s):  
Jeff Th. M. De Hosson ◽  
George Palasantzas ◽  
Tomas Vystavel ◽  
Siete Koch
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Self Assembly ◽  
Cluster Size ◽  
Elevated Temperatures ◽  
Crystal Habit ◽  
In Situ Tem ◽  
Transmission Electron ◽  
The Face

ABSTRACTThe paper concentrates on in situ transmission electron microscopy of nano-sized Mo and Nb clusters. In particular, this contribution presents challenges to control the microstructure in nano-structured materials via a relatively new approach, i.e. using a so-called nanocluster source. An important aspect is that the cluster size distribution is monodisperse and that the kinetic energy of the clusters during deposition can be varied. The deposited Mo clusters with sizes 5 nm or larger show a body-centered crystal (bcc) structure. The cubic clusters are self-assembled from smaller ones and forming distorted cubes of typical size 7.8 nm or larger. With reducing cluster size to ≤3 nm, the face centered crystal (fcc) structure appears due to dominance of surface energy minimization, while self-assembly into large cubes with sizes up to 20 nm is still observed. In situ TEM annealing leads to cluster coalescence at temperatures ∼800 °C, with the crystal habit changing to rhombic dodecahedron for isolated clusters, while large cubes change to faceted polyhedra. In situ TEM annealing studies on Nb clusters showed that cluster coalescence events were not observed even at rather elevated temperatures because of the formation of oxides.

Sign in / Sign up

Export Citation Format

Share Document