scholarly journals Utilizing TiO 2 amorphous precursors for polymorph selection: An in situ TEM study of phase formation and kinetics

2019 ◽  
Vol 103 (4) ◽  
pp. 2899-2907 ◽  
Author(s):  
John S. Mangum ◽  
Lauren M. Garten ◽  
David S. Ginley ◽  
Brian P. Gorman
Keyword(s):  
Phase Formation ◽  
In Situ Tem ◽  
Polymorph Selection

In-Situ TEM Observation on Phase Formation of TiO2 Nanoparticle Synthesized by Flame Method

2007 ◽  
pp. 81-84
Author(s):  
Hoon Park ◽  
H.S. Jie ◽  
Kyou Hyun Kim ◽  
Jae Pyong Ahn ◽  
Jong Ku Park
Keyword(s):  
Phase Formation ◽  
In Situ Tem ◽  
Flame Method

In-Situ TEM Phase Formation in Cold Rolled Aluminum-Nickel Multilayers

1997 ◽  
Vol 481 ◽  
Author(s):  
H. Sieber ◽  
J. H. Perepezko
Keyword(s):  
Cold Rolling ◽  
Phase Formation ◽  
In Situ Tem ◽  
3 Dimensional ◽  
Thermally Activated ◽  
Dsc Measurements ◽  
Sem And Tem ◽  
Rolled Aluminum ◽  
Cold Rolled

ABSTRACTMultilayer samples of Nickel and Aluminum with an overall composition of Al-20Ni were prepared by cold rolling of elemental foils. The sample microstructures and phases were characterized by XRD, SEM and TEM/SAED, and the reactive phase formation was then examined by DSC measurements. XRD, SEM and TEM measurements show that the rolling procedure results in a decrease of the Al and Ni layer thicknesses (down to 100 nm in average) and a decrease of the grain size (down to less than 50 nm). No phase formation is observed during the cold rolling procedure. In isochronal DSC scans of the Al-Ni multilayers, the formation of the Al3Ni phase was found to be a two step reaction process due to 2-dimensional nucleation and lateral growth and a 3-dimensional phase thickening. While XRD measurements showed Al3Ni as the only phase that forms, more detailed TEM investigations of the samples after DSC treatment also showed a small amount of an amorphous Al-Ni phase, formed by a thermally activated solid state amorphization reaction (SSAR). In-situ TEM heating of the amorphous areas under the electron beam in the microscope yielded the crystallization of the amorphous phase to a B2 structure and a growth of the B2 grains up to 100 nm in size.

An in situ TEM study of phase formation in gold-aluminum couples

2004 ◽  
Vol 39 (1) ◽  
pp. 165-171 ◽  
Author(s):  
D. E. Eakins ◽  
D. F. Bahr ◽  
M. G. Norton
Keyword(s):  
Phase Formation ◽  
In Situ Tem

scholarly journals Early Stages of Secondary Phase Formation in Multicomponent Alloys Using an in situ TEM Heating Approach

2019 ◽  
Vol 25 (S2) ◽  
pp. 1536-1537
Author(s):  
Elaf A. Anber ◽  
Eric A. Lass ◽  
Andrew C Lang ◽  
Pranav Kumar Suri ◽  
Daniel Scotto D'Antuono ◽  
...  
Keyword(s):  
Phase Formation ◽  
Secondary Phase ◽  
In Situ Tem ◽  
Multicomponent Alloys ◽  
Early Stages ◽  
Secondary Phase Formation

In situ TEM studies of irradiation effects for materials improvement

1991 ◽  
Vol 49 ◽  
pp. 452-453
Author(s):  
Charles W. Allen
Keyword(s):  
Nuclear Reactor ◽  
Austenitic Stainless Steels ◽  
High Energy ◽  
Point Of View ◽  
In Situ Tem ◽  
Irradiation Effects ◽  
Tem Analysis ◽  
Radiation Induced ◽  
Analytical Tools

Irradiation effects studies employing TEMs as analytical tools have been conducted for almost as many years as materials people have done TEM, motivated largely by materials needs for nuclear reactor development. Such studies have focussed on the behavior both of nuclear fuels and of materials for other reactor components which are subjected to radiation-induced degradation. Especially in the 1950s and 60s, post-irradiation TEM analysis may have been coupled to in situ (in reactor or in pile) experiments (e.g., irradiation-induced creep experiments of austenitic stainless steels). Although necessary from a technological point of view, such experiments are difficult to instrument (measure strain dynamically, e.g.) and control (temperature, e.g.) and require months or even years to perform in a nuclear reactor or in a spallation neutron source. Consequently, methods were sought for simulation of neutroninduced radiation damage of materials, the simulations employing other forms of radiation; in the case of metals and alloys, high energy electrons and high energy ions.

In situ TEM measurements of the electrical properties of interface dislocations

1992 ◽  
Vol 50 (2) ◽  
pp. 1338-1339
Author(s):  
F. M. Ross ◽  
R. Hull ◽  
D. Bahnck ◽  
J. C. Bean ◽  
L. J. Peticolas ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Electronic Device ◽  
In Situ Tem ◽  
Device Performance ◽  
Misfit Dislocations ◽  
Electrical Characteristics ◽  
Strained Layer ◽  
Transmission Electron ◽  
Interfacial Dislocations

We describe an investigation of the electrical properties of interfacial dislocations in strained layer heterostructures. We have been measuring both the structural and electrical characteristics of strained layer p-n junction diodes simultaneously in a transmission electron microscope, enabling us to correlate changes in the electrical characteristics of a device with the formation of dislocations.The presence of dislocations within an electronic device is known to degrade the device performance. This degradation is of increasing significance in the design and processing of novel strained layer devices which may require layer thicknesses above the critical thickness (hc), where it is energetically favourable for the layers to relax by the formation of misfit dislocations at the strained interfaces. In order to quantify how device performance is affected when relaxation occurs we have therefore been investigating the electrical properties of dislocations at the p-n junction in Si/GeSi diodes.

In situ TEM Studies of agglomeration of sub-nanometer Ru layers in Ru/C multilayers

1992 ◽  
Vol 50 (1) ◽  
pp. 256-257
Author(s):  
Tai D. Nguyen ◽  
Ronald Gronsky ◽  
Jeffrey B. Kortright
Keyword(s):  
Layered Structure ◽  
Driving Force ◽  
High Energy ◽  
Superior Performance ◽  
In Situ Tem ◽  
Rayleigh Instability ◽  
Practical Applications ◽  
Transmission Electron ◽  
Diffraction Patterns

Nanometer period Ru/C multilayers are one of the prime candidates for normal incident reflecting mirrors at wavelengths < 10 nm. Superior performance, which requires uniform layers and smooth interfaces, and high stability of the layered structure under thermal loadings are some of the demands in practical applications. Previous studies however show that the Ru layers in the 2 nm period Ru/C multilayer agglomerate upon moderate annealing, and the layered structure is no longer retained. This agglomeration and crystallization of the Ru layers upon annealing to form almost spherical crystallites is a result of the reduction of surface or interfacial energy from die amorphous high energy non-equilibrium state of the as-prepared sample dirough diffusive arrangements of the atoms. Proposed models for mechanism of thin film agglomeration include one analogous to Rayleigh instability, and grain boundary grooving in polycrystalline films. These models however are not necessarily appropriate to explain for the agglomeration in the sub-nanometer amorphous Ru layers in Ru/C multilayers. The Ru-C phase diagram shows a wide miscible gap, which indicates the preference of phase separation between these two materials and provides an additional driving force for agglomeration. In this paper, we study the evolution of the microstructures and layered structure via in-situ Transmission Electron Microscopy (TEM), and attempt to determine the order of occurence of agglomeration and crystallization in the Ru layers by observing the diffraction patterns.

Sign in / Sign up

Export Citation Format

Share Document