Electrochemical Phase Formation of Metals and Alloys at Chemically Identical Solid or Liquid Cathode: Part 1. Metals

<p class="AMSmaintext"><span lang="EN-GB">The aim of this work was further experimental verification of the existence of the phenomenon of electrochemical phase formation in metals and alloys via a supercooled liquid state stage. According to proposed idea the slowing down of the process of polymorphic transformation in a metal being electrodeposited should be accompanied by an intensive formation of the texture of the metastable modification and suppression of the texture development of the stable modification. The results of the texture analysis of electrodeposited cobalt as a model metal showed that under slowing down the polymorphic transformation process in a metal being electrodeposited, the texture formation is intensified in the metastable modification, but suppressed in the stable modification. The finding is another proof of the existence of the phenomenon of electrochemical phase formation in metals and alloys through a supercooled liquid state stage.</span></p>

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Some Applications of the U. S. Steel MVEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070461 ◽

1973 ◽

Vol 31 ◽

pp. 4-5

Author(s):

J. S. Lally ◽

L. E. Thomas ◽

R. M. Fisher

Keyword(s):

Electron Diffraction ◽

Debye Temperature ◽

Metals And Alloys ◽

Critical Voltage ◽

Dynamical Diffraction ◽

Phase Structures ◽

Structure Factors ◽

Local Bonding ◽

Diffraction Phenomenon ◽

Multi Phase

A variety of materials containing many different microstructures have been examined with the USS MVEM. Three topics have been selected to illustrate some of the more recent studies of diffraction phenomena and defect, grain and multi-phase structures of metals and minerals.(1) Critical Voltage Effects in Metals and Alloys - This many-beam dynamical diffraction phenomenon, in which some Bragg resonances vanish at certain accelerating voltages, Vc, depends sensitively on the spacing of diffracting planes, Debye temperature θD and structure factors. Vc values can be measured to ± 0.5% in the HVEM ana used to obtain improved extinction distances and θD values appropriate to electron diffraction, as well as to probe local bonding effects and composition variations in alloys.

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Characterization of reactive phase formation in sputter-deposited Ni/Al multilayer thin films using TEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100167469 ◽

1996 ◽

Vol 54 ◽

pp. 1000-1001

Author(s):

G. Lucadamo ◽

K. Barmak ◽

C. Michaelsen

Keyword(s):

Thin Films ◽

Phase Formation ◽

Dark Field ◽

Nickel Layer ◽

Multilayer Thin Films ◽

Cross Sectional ◽

Dark Field Imaging ◽

Transmission Electron ◽

Sputter Deposited ◽

Constant Heating

The subject of reactive phase formation in multilayer thin films of varying periodicity has stimulated much research over the past few years. Recent studies have sought to understand the reactions that occur during the annealing of Ni/Al multilayers. Dark field imaging from transmission electron microscopy (TEM) studies in conjunction with in situ x-ray diffraction measurements, and calorimetry experiments (isothermal and constant heating rate), have yielded new insights into the sequence of phases that occur during annealing and the evolution of their microstructure.In this paper we report on reactive phase formation in sputter-deposited lNi:3Al multilayer thin films with a periodicity A (the combined thickness of an aluminum and nickel layer) from 2.5 to 320 nm. A cross-sectional TEM micrograph of an as-deposited film with a periodicity of 10 nm is shown in figure 1. This image shows diffraction contrast from the Ni grains and occasionally from the Al grains in their respective layers.

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