Development of surface relief on polycrystalline metals due to sputtering

Abstract

The characteristics of surface microrelief that appear in sputtering experiments with polycrystalline metals of various grain sizes have been studied. Specimens with grain sizes varying from 30 -70 nm in the case of crystallized amorphous alloys, to 1 -3 µm for technical tungsten grade and 10 -100 μm for recrystallized tungsten were investigated. A model is proposed for the development of roughness on polycrystalline metals which is based on the dependence of sputtering rate on crystal orientation. The results of the modeling are in good agreement with experiments showing that the length scale of roughness is much larger than the grain size. Voitsenya et al.Surface relief due to sputtering of polycrystalline metals

Deuterium retention and morphological modifications of the surface in five grades of tungsten after deuterium plasma exposure

“…For the recrystallized specimen rc-WJ, no conclusive texture analysis was possible due to the large grain size and the statistical small number of analysed grains. An orientation analysis in the frame of another study on such recrystallized specimens [29] points to a soft texture with a higher amount of grains close to (110) and a lower amount of grains close to (111).…”

“…The D inventory results from the integration of the depth profile and is an average value over the area of the analysing spots. More details on the experimental set-up for the nuclear reaction analysis (NRA), the depth resolution and the data evaluation can be found in [7,8,29,31,32].…”

Experimental Simulation of the Behaviour of Diagnostic First Mirrors Fabricated of Different Metals for ITER Conditions

“…3b) that a small deviation (~9°) from the exact orientation of the (111) face lying on the surface did not change much of its sputtering rate compared to the others. This fact was used as a qualitative basis for modeling of the relief that develops on the polycrystalline mirror under sputtering [11], (see below). It may be evident that a "stepped" surface relief results in degradation of the optical properties of the mirror.…”

“…The authors of ref [11] have analysed the results of long-duration sputtering experiments on polycrystalline metal mirrors with crystal grains of different sizes ranging from tens of nanometers to tens of micrometers. Included in their study were: (i) mirrors produced through annealing of amorphous alloys (crystallite size 30 to 70 nm); (ii) thin film mirrors (Rh film on a Cu substrate, crystallite size being ~100 nm); (iii) fine-grained Cu, Mo and W mirrors (grain size 250-350 nm); (iv) ITER-grade tungsten mirrors with strong anisotropy of grains (grain size being 1-3 μm and ~5 μm along the surface and perpendicular to it, respectively), and (v) tungsten mirrors that were recrystallized at 2073 K after high-quality polishing (grain size between 10 and 100 μm [10]).…”

“…Included in their study were: (i) mirrors produced through annealing of amorphous alloys (crystallite size 30 to 70 nm); (ii) thin film mirrors (Rh film on a Cu substrate, crystallite size being ~100 nm); (iii) fine-grained Cu, Mo and W mirrors (grain size 250-350 nm); (iv) ITER-grade tungsten mirrors with strong anisotropy of grains (grain size being 1-3 μm and ~5 μm along the surface and perpendicular to it, respectively), and (v) tungsten mirrors that were recrystallized at 2073 K after high-quality polishing (grain size between 10 and 100 μm [10]). The relief data obtained with the use of an atomic force microscope (AFM) or a laser profilometer were analysed in detail, and based on that, a model for the roughness development on PC mirrors during sputtering has been developed; its detailed description can be found in ref [11].…”