Diffusion of Radioactive Copper during Oxidation of Copper Foil

Castellan, Gilbert W.; Moore, Walter J.

doi:10.1063/1.1747051

Cited by 44 publications

(7 citation statements)

References 4 publications

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“…Because it is known that the diffusion of zinc ions is slower in zinc oxide than copper ions in cuprous oxide (10)(11)(12), a reasonable assumption is that, because of the marked differences in the structures of zinc oxide (hexagonal close-packed of the wurtzite type) and cuprous oxide (cubic), copper ions also diffuse more slowly in zinc oxide than in cuprous oxide. In addition, because cuprous oxide and zinc oxide are virtually immiscible, the diffusion of copper in zinc oxide is expected to be very small.…”

mentioning

confidence: 99%

The Role of a Displacement Reaction in the Kinetics of Oxidation of Alloys

Levin¹,

Wagner²

1961

J. Electrochem. Soc.

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mentioning

confidence: 99%

The Role of a Displacement Reaction in the Kinetics of Oxidation of Alloys

Levin¹,

Wagner²

1961

J. Electrochem. Soc.

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“…The scale may also be sectioned to determine the tracer distribution, analysis of which should reveal whether a bulk or a short-circuiting diffusion mechanism is operative. If normal lattice transport is indicated and there are no other complications, the cation diffusion coefficient calculated from the slope of the In c vs. x 2 plot should agree reasonably well with the self-diffusion coefficient measured by more conventional techniques (35,36,38). This would provide still another check on the assumed transport mechanism.…”

Section: Discussionmentioning

confidence: 52%

“…In most experiments of this kind thus far reported which involve the growth of thick scales on metals, only the distribution of the radioactive cation has been investigated (31,(33)(34)(35)(36)(37)(38). In a few cases, however, the radioactive isotope S 35 has been utilized in studying the mechanism of sulfidization (39-41} of metals and alloys.…”

Section: Techniques Utilizing Radioactive Components Of the System As...mentioning

confidence: 99%

Marker Techniques for Studying the Mechanism of Scaling of Metals Based on the Use of the O[sup 18](p,n)F[sup 18] Nuclear Reaction

Holt

Himmel

1969

J. Electrochem. Soc.

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A general mechanistic approach to the study of scaling reactions is proposed which dispenses with the conventional inert marker. Instead, radioisotopes of the reacting components are used to establish the nature of the diffusing species in the solid reaction products formed on metal surfaces at high temperatures. For investigating the mechanism of oxidation of metals, O TM is employed as a tracer and the stable isotope is subsequently activated by proton bombardment via the nuclear reaction O1S(p,n)F Is. The basis for the technique is outlined and its application to the scaling of iron and of zirconium is described. The experiments with iron establish conclusively that, at temperatures up to I050~ iron is the only diffusing component in the dense, adherent wi~stite layer which forms adjacent to the metal. Direct evidence is also presented for the vapor phase transport of oxygen by a dissociative mechanism during the growth of porous, non-adherent wfistite scales on iron in H~/H.~O atmospheres. It is shown that oxygen is mobile in thick ZrO2 scales formed on Zr in a water vapor atmosphere at 1200~ however, the unusual form of the O Is distribution in the scale indicates that open channels must have existed in the outer portion of the scale during oxidation which allowed direct penetration of oxygen to levels deep within the ZrO2 layer. The advantages and limitations of the present technique are discussed with particular reference to conventional marker methods. Major sources of difficulty in the interpretation of inert marker experiments are identified and a set of experimental requirements is given which, if satisfied, should permit reliable transport information to be obtained using conventional marker techniques.The mechanism of a heterogeneous chemical reaction, such as the oxidation of a metal, can be considered established, at least in principle, if the rate-determining step in the reaction is known and if the manner in which the reactants are transported to and from the various phase boundaries in the system can be specified. Information of this kind cannot generally be obtained from kinetic studies alone. In fact, even under conditions where diffusion-controlled kinetics are observed, it is often not possible to decide, unambiguously, whether the reaction is sustained by the outward migration of metal ions through the scale, or by the inward diffusion of the nonmetallic component. The dominant or faster diffusing species can, of course, be predicted if self-diffusion or ionic conductivity data are available for both components over the entire stability range of the product phase. Unfortunately, reliable data of this type currently exist for only a few oxide and sulfide systems (1-3).When the necessary transport data are not available, inert marker techniques are customarily employed to determine the nature of the mobile component in the growing scale. Marker methods were first introduced by Pfeil (4) in 1929 in his classic work on the scaling of iron, and they have been applied subsequently to a great many...

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“…As discussed in ref. [22], Cu and Ni are segregated during oxidation of Cu-Ni alloys because of the much larger lattice diffusion coefficient of Cu in Cu 2 O with respect to that of Ni in NiO (at 1173 K, ~10 -9 cm 2 s -1 [26] and ~10 -13 cm 2 s -1 [27], respectively). The different mobility of the metallic ions in the corresponding oxides generates an excess of vacancies that tend to coalesce, leading to the formation of pores according to the Kirkendall effect, as often observed in the oxidation process of bimetallic alloys, such as alpha brass [28].…”

Section: Resultsmentioning

confidence: 99%

Nanoporous microtubes obtained from a Cu-Ni metallic wire

et al. 2016

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Nanoporous microtubes of a nickel-copper alloy were obtained from a Cu-44Ni-1Mn (wt.%) wire (200 µm diameter). A new synthesis method was established through three steps: 1) partial oxidation of the wire at 1173 K in air, 2) removal of the inner unoxidized core by chemical etching, 3) reduction in 10 bar hydrogen atmosphere. During oxidation, the segregation of Cu and Ni occured because of their different diffusion coefficients in the corresponding oxides. As a consequence, pores were formed by Kirkendall effect and due to selective chemical etching of the different oxides. Additional porosity formed because of volume contraction during reduction with hydrogen.The process allowed to obtain microtubes with tuneable wall thickness and inner pores around 180 ± 80 nm. The morphological features developed suggest improved capillarity properties for applications in MEMS.

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Diffusion of Radioactive Copper during Oxidation of Copper Foil

Cited by 44 publications

References 4 publications

The Role of a Displacement Reaction in the Kinetics of Oxidation of Alloys

The Role of a Displacement Reaction in the Kinetics of Oxidation of Alloys

Marker Techniques for Studying the Mechanism of Scaling of Metals Based on the Use of the O[sup 18](p,n)F[sup 18] Nuclear Reaction

Nanoporous microtubes obtained from a Cu-Ni metallic wire

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