Growth of Lamellar Products During Discontinuous Solid State Reactions

1999 ◽  
Vol 580 ◽  
Author(s):  
P. Zieba ◽  
W. Gust
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Discontinuous Precipitation ◽  
Analytical Electron Microscopy ◽  
Morphological Features ◽  
Solid State Reactions ◽  
Analytical Electron ◽  
Nucleation Growth

AbstractThe nucleation, growth and dissolution of lamellar precipitates formed due to discontinuous solid state reactions like: discontinuous precipitation, coarsening and dissolution, are reviewed. Emphasis is given on recent studies based on analytical electron microscopy in describing the microchemistry, and in situ electron microscopy for revealing the morphological features of the reactions.

Application of analytical electron microscopy to the study of partitioning of silicon in a 2 wt% Si eutectoid steel

1978 ◽  
Vol 36 (1) ◽  
pp. 616-617
Author(s):  
N. Ridley ◽  
S.A. Al-Salman ◽  
G.W. Lorimer
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Analytical Electron Microscopy ◽  
Eutectoid Steel ◽  
Minimum Diameter ◽  
Thin Foils ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Transformation Front

The application of the technique of analytical electron microscopy to the study of partitioning of Mn (1) and Cr (2) during the austenite-pearlite transformation in eutectoid steels has been described in previous papers. In both of these investigations, ‘in-situ’ analyses of individual cementite and ferrite plates in thin foils showed that the alloying elements partitioned preferentially to cementite at the transformation front at higher reaction temperatures. At lower temperatures partitioning did not occur and it was possible to identify a ‘no-partition’ temperature for each of the steels examined.In the present work partitioning during the pearlite transformation has been studied in a eutectoid steel containing 1.95 wt% Si. Measurements of pearlite interlamellar spacings showed, however, that except at the highest reaction temperatures the spacing would be too small to make the in-situ analysis of individual cementite plates possible, without interference from adjacent ferrite lamellae. The minimum diameter of the analysis probe on the instrument used, an EMMA-4 analytical electron microscope, was approximately 100 nm.

Solid-State Reactions in Fe/Si Multilayer Nanofilms

2014 ◽  
Vol 215 ◽  
pp. 144-149 ◽  
Author(s):  
Sergey M. Zharkov ◽  
Roman R. Altunin ◽  
Evgeny T. Moiseenko ◽  
Galina M. Zeer ◽  
Sergey N. Varnakov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid State ◽  
Electron Diffraction ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Solid State Reactions ◽  
Transmission Electron ◽  
Reaction Processes

Solid-state reaction processes in Fe/Si multilayer nanofilms have been studied in situ by the methods of transmission electron microscopy and electron diffraction in the process of heating from room temperature up to 900ºС at a heating rate of 8-10ºС/min. The solid-state reaction between the nanolayers of iron and silicon has been established to begin at 350-450ºС increasing with the thickness of the iron layer.

Analytical Electron Microscopy Studies of Bi-Substituted Garnet Films

1991 ◽  
Vol 232 ◽  
Author(s):  
P. A. Crozier ◽  
P. A. Labun ◽  
T Suzuki
Keyword(s):  
Electron Microscopy ◽  
Analytical Electron Microscopy ◽  
Second Phase ◽  
Processing Conditions ◽  
Transformation Kinetics ◽  
Heating Rates ◽  
Garnet Films ◽  
Analytical Electron ◽  
In Situ Heating

ABSTRACTIn-situ heating in an electron microscope, together with EDX and EELS analysis, was used to characterize as-deposited amorphous and transformed garnet films. It was found that upon initial crystallization, a non-uniform precipitation of a second phase occurred, altering the local chemistry and microstructure of the transformed film. In addition, to study the transformation kinetics in more detail some experiments were conducted at slower heating rates and lower temperatures. It is hoped that the data obtained can be correlated to magnetic property measurements and contribute to the development of improved processing conditions.

Concurrent In Situ Formation of Ag / Ag2S Nanoparticles in Polymer Matrix by Facile Polymer-Inorganic Solid State Reaction

2009 ◽  
Vol 5 ◽  
pp. 143-152
Author(s):  
Sujata Waghmare ◽  
Manish Shinde ◽  
Ramkrishna Gholap ◽  
N. Koteswara Rao ◽  
Ranjit R. Hawaldar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Solid State Reaction ◽  
Polymer Network ◽  
Morphological Features ◽  
Molar Ratio ◽  
Simultaneous Occurrence ◽  
Metallic Silver ◽  
Molar Ratios

We herein report the feasibility of polymer-inorganic solid-state reaction route for simultaneous in situ generation of Ag & Ag2S nanostructures in polymer network wherein an engineering thermoplastic, polyphenylene sulphide (PPS), itself acts as a chalcogen source as well as a stabilizing matrix for the resultant nanoproducts. Typical solid-state reaction was accomplished by simply heating the physical admixture of the two reactants i.e. AgNO3 and PPS by varying molar ratios mainly 1:1, 1:5, 1:15, 1:20, at the crystalline melting temperature (285 °C) of PPS. The synthesized nanoparticles were characterized by various physico-chemical techniques like X-ray Diffractometry, Scanning Electron Microscopy equipped with EDAX, Transmission Electron Microscopy and UV-Visible spectroscopy. The prima facie observations suggest the effective formation and subsequent entrapment of mainly nanocrystalline metallic silver (fcc) in PPS matrix for all the molar ratios chosen for the reaction. Additionally, simultaneous occurrence of nanocrystalline Ag2S (monoclinic phase) is also noticed in case of heated admixture of AgNO3: PPS with equimolar ratio. The TEM analysis reveals nanoscale polydispersity (5nm to 70nm) and prevalence of mainly spherical morphological features in all the cases with occasional indications of triangular and hexagonal morphological features depending upon the reaction molar ratio.

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