Revisiting the 12C(d, p)13C reaction cross section using condensed gas targets

Lennard, W. N.; Massoumi, G.R.; Alkemade, P.F.A.; Mitchell, I.V.; Tong, S. Y.

doi:10.1016/0168-583x(91)95552-o

Cited by 25 publications

(11 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Details of the analysis of 16 O by NRA can be found elsewhere [24]. The carbon content was estimated from the ratio of the yields of the O reactions, using literature values of the respective cross-sections [25]. Fluorine could not be quantified by NRA, due to lack of data on the reaction cross-sections.…”

Section: Methodsmentioning

confidence: 99%

Effect of current density and behaviour of second phases in anodizing of a Mg-Zn-RE alloy in a fluoride/glycerol/water electrolyte

Němcová

Kuběna

Šmíd

et al. 2015

J Solid State Electrochem

View full text Add to dashboard Cite

Anodizing of a Mg-Zn-RE alloy was carried out at constant current densities from 0.1 to 10 mA cm −2 in a fluoride/glycerol/water electrolyte. Rutherford backscattering spectroscopy, nuclear reaction analysis and analytical transmission electron microscopy revealed barrier-type films composed of oxide and fluoride species. The films were formed by outward migration of cations and inward migration of anions. The transport number of cations in the film above the matrix was in the range ∼0.5 to 0.6, and ∼0.1 in the film above the grain boundary Mg-Zn-RE phase. From the oxidation behaviour of the Zn-Zr phases, it is suggested that anions and cations migrate through short-circuit paths in the film.

show abstract

Section: Methodsmentioning

confidence: 99%

Effect of current density and behaviour of second phases in anodizing of a Mg-Zn-RE alloy in a fluoride/glycerol/water electrolyte

Němcová

Kuběna

Šmíd

et al. 2015

J Solid State Electrochem

View full text Add to dashboard Cite

show abstract

“…The oxygen contents were quantified to an accuracy of ∼3% using a reference specimen of anodized tantalum. Details of the analysis of 16 O by NRA can be found elsewhere. 14,15 The carbon content was estimated from the ratio of the yields of the 12 C(d,p 0 ) 13 C and 16 O(d,p 1 ) 17 O using literature values of the cross-sections for the respective reactions.…”

Section: Specimen Characterization-mentioning

confidence: 99%

Formation of a Trivalent Chromium Conversion Coating on AA2024-T351 Alloy

Hashimoto

Walton

et al. 2015

J. Electrochem. Soc.

105

View full text Add to dashboard Cite

The formation of a trivalent chromium conversion coating on AA2024-T351 aluminum alloy has been studied using electron microscopy, scanning Kelvin probe force microscopy, ion beam analysis and X-ray photoelectron spectroscopy (XPS). The coating contained oxide, hydroxide, fluoride and sulfate species, and consisted of two main layers: a zirconium-and chromium-rich outer layer and a thinner, aluminum-rich, inner layer. XPS indicated that zirconium and chromium are mainly present as ZrO 2 , Cr(OH) 3 , Cr 2 (SO 4 ) 3 and CrF 3 . In addition, a thin aluminum-rich layer, probably composed of hydrated alumina, occurred transiently at the coating surface. The coating above cathodic second phase particles was usually thicker than that above the matrix due to the locally increased alkalinity. In the early stages of treatment, the thickest coating formed above the S-phase particles. Localized corrosion and copper enrichment of the matrix occurred at the coating base. The localized corrosion is possibly related to the observed accumulation of fluoride ions at the inner layer and the enrichment of copper in the alloy. The thickness of the coating above the alloy matrix was significantly less than that of a coating formed on high purity aluminum. AA2024-T3 aluminum alloy is widely used in the aerospace industry due to its high strength to weight ratio and damage tolerance. However, the presence of copper as a primary alloying element leads to an increased susceptibility to localized corrosion, especially pitting corrosion.2,3 Hence, the alloy requires protective treatments to provide the required corrosion resistance for many applications. Such treatments often involve the use of chromate conversion coatings. However, the toxicity and high disposal costs of Cr(VI) wastes necessitate the development of eco-friendly alternatives. 4,5 One promising candidate treatment uses a trivalent chromium bath, generally consisting of zirconium hexafluoride and trivalent chromium salts. 6,7 The coating formation involves the dissolution of the native oxide on the aluminum surface due to the acidic, fluoride-containing solution, 8 and the subsequent pH-driven deposition of zirconium and chromium species. The increase in interfacial pH is promoted by the cathodic reactions, i.e. hydrogen evolution and/or oxygen reduction. 9Previous work has indicated that the resultant coating consists of two layers. 7,9,10 In one study, it was proposed that a first, dense layer is formed by hydrolysis of Cr(OH) x (3-x)+ and Zr(OH) x (4-x)+ ions that retards oxidation of the alloy and reduction of protons; a second layer then forms by preferential deposition of zirconium hydroxide at transient cathodic sites.10 Other studies revealed a coating composed of an outer, hydrated zirconium-rich layer that also contains chromium species and an inner, aluminum-rich layer. 7,9 Several investigations have been carried out to determine whether Cr(VI) species are formed in trivalent chromium conversion coatings. No Cr(VI) was detected by UV-visible spectroscopy in as-de...

show abstract

“…26 The carbon content was estimated from the ratio of the yields of the 12 C(d,p 0 ) 13 C and 16 O(d,p 1 ) 17 O using literature values of the cross-sections for the respective reactions. 27 Fluorine could not be quantified by NRA due to the lack of data on the reaction cross-sections. The accuracy of the measurements of the fluorine and oxygen contents of films, determined by RBS and NRA respectively, was ∼5%.…”

Section: ×10mentioning

confidence: 99%

Behavior of Alloying Elements during Anodizing of Mg-Cu and Mg-W Alloys in a Fluoride/Glycerol Electrolyte

Palagonia

Němcová

Kuběna

et al. 2015

J. Electrochem. Soc.

View full text Add to dashboard Cite

Anodizing of sputtering-deposited magnesium and Mg-0.75at.%Cu and Mg-1.23at.%W alloys has been carried out in a fluoride/glycerol electrolyte. The aims of the study were to investigate the enrichment of alloying elements in the alloy immediately beneath the anodic film and the migration of alloying element species in the film. The specimens were examined by electron microscopy and ion beam analysis. An enrichment of copper is revealed in the Mg-Cu alloy that increases with the anodizing time up to ∼6×10 15 Cu atoms cm −2 . Copper species are then incorporated into the anodic film and migrate outwards. In contrast, no enrichment of tungsten occurs in the Mg-W alloy, and tungsten species are immobile in the film. Anodizing treatments have long been used for the protection of magnesium alloys against corrosion and wear and interest still remains in improving and extending the range of available technologies. [1][2][3][4][5][6] Nevertheless, fundamental knowledge of anodizing of magnesium, 7 for instance relating to the migration rates and transport numbers of film species, is comparatively limited, in part due to the difficulty of forming films of uniform composition and thickness, and also to their reactivity to water. The formation of barrier-type anodic films has been extensively investigated on the valve metals, especially for aluminum, niobium, tantalum, titanium and zirconium.8 These studies have shown that oxide films of uniform thickness are formed under a high electric field that depends upon the film composition and the rate of film growth. [8][9][10] The films on aluminum, tantalum and niobium are usually amorphous, 8 and their formation involves migration of metal ions and oxygen ions, with significant contributions of both types, e.g. the transport numbers of Al 3+ , Nb 5+ and Ta 5+ are ∼0.40, 0.24 and 0.24 respectively. 8 Further, an outer region of the oxide films often contains a low concentration of species derived from the anions of the electrolyte.11 In contrast, the films on zirconium are usually nanocrystalline and form mainly by migration of O 2− ions, 12,13 while films on titanium undergo a transition from amorphous oxide to a mixture of amorphous and crystalline oxide.14 Barrier-type films can also be formed on magnesium, although such films have received much less attention and, consequently, less is known of the details of their composition, structure and growth mechanism. Films formed in aqueous electrolytes are often reported to consist of MgF 2 , MgO and/or Mg(OH) 2 . 5,7,[15][16][17] Barrier-type films can also be formed using non-aqueous electrolytes and the formation of uniform films in such electrolytes provides the opportunity for systematic studies of the anodizing behavior. 18,19 From previous work, anodizing of magnesium alloys can result in the enrichment of alloying elements beneath the anodic film. Such enrichments have been reported for copper, tungsten and zinc beneath oxide/hydroxide films formed on model alloys in an aqueous electrolyte 20,21 and of zinc beneath fluoride-...

show abstract

Revisiting the 12C(d, p)13C reaction cross section using condensed gas targets

Cited by 25 publications

References 18 publications

Effect of current density and behaviour of second phases in anodizing of a Mg-Zn-RE alloy in a fluoride/glycerol/water electrolyte

Effect of current density and behaviour of second phases in anodizing of a Mg-Zn-RE alloy in a fluoride/glycerol/water electrolyte

Formation of a Trivalent Chromium Conversion Coating on AA2024-T351 Alloy

Behavior of Alloying Elements during Anodizing of Mg-Cu and Mg-W Alloys in a Fluoride/Glycerol Electrolyte

Contact Info

Product

Resources

About