Anodization behaviour and basic property mapping in the aluminium-erbium system

Abstract

A co-evaporation technique was used for depositing an Al-Er thin film combinatorial library on borosilicate glass substrates with Er concentrations between 3 and 21 at.% and a total compositional resolution of 0.25 at.% mm −1. Scanning droplet cell microscopy was employed for compositional mapping of several fundamental properties of mixed oxides grown on Al-Er thin film alloys. Microstructural and crystallographic particularities of Al-Er alloys were identified along the library, and a relevant compositional threshold at around Al-5 at.% Er was identified. Further, small surface grains in the nanometre range were found at Al grain boundaries, and an initial amorphization and/or hexagonal phase nucleation was identified for Er amounts around 5 at.%. Electrochemical studies revealed the importance of this compositional threshold, as distinct maximizations of oxide formation factors and oxide electrical permittivities were observed.

A theoretical and experimental framework for the formation of mixed anodic films on combinatorial aluminium-cerium alloys

“…Careful examination of the XRD pattern indicates that high peak intensity maintained until Al-5.5 at.% Ce and thereafter, the peak intensity sharply decreases to lower value and disappeared completely at 10.5 at.% Ce. As reported for another Al-RE system [33] , a slight shift of the fcc-Al(111) started to be visible only at Er concentration higher than 15 at.% and no apparent peak shift was observable below this concentration. Similarly, a visible peak shift was not observed in the Al-Ce system within the studied concentrations.…”

“…None of these techniques describe the fabrication of thin Ce oxide films especially the systematic investigation of the effect of Ce concentration on the resulting oxide properties in Al-Ce alloys. Literature data reveals that among various oxidation techniques, anodic polarization is a simple, fast, environmentally friendly, and the cost-effective method of thin film oxidation for an alloy having complex chemistry [33][34][35][36].…”

Corrosion and Structural Properties of Erbium–Zinc Thin Films at Low‐to‐Medium Erbium Concentrations

“…Similarly, Hf–Ta alloys showed a tendency for amorphization due to a simultaneous change in the crystallographic system and change in average lattice mismatch at 60–70 at% Ta . In Al–Er, no amorphization occurred because the mismatch was not strong enough . The induced mismatch due to the rare earth addition should be higher with Zn because the atom has a smaller radius.…”

Combinatorial Passivation Study in the Aluminium-Samarium System for Basic Property Mapping and Identification of Secondary Phase Influence

“…Some rare earth elements are also reported to increase the electromigration resistance of Al. 14,15 One paper on a single Al-Sm composition reports on the formation of a thicker oxide investigated by TEM, which consists of a pure Sm 2 O 3 film in the outermost region. 16 To utilize such special characteristics, the composition dependences should be systematically investigated.…”

“…It is part of a systematic series of Al-RE alloys in which the influence of the lanthanoid contraction shall be investigated over a wide range of compositions similar to the Al-Tb 12 and Al-Er systems. 14…”