Nanoindentation of Silicon and Germanium

Kiran, M. S. R. N.; Haberl, Bianca; Bradby, Jodie; Williams, James S.

doi:10.1016/bs.semsem.2014.12.002

Cited by 9 publications

(4 citation statements)

References 94 publications

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“…Due to indentation size effects, hardness values in the range of 11.3-12.5 GPa were measured for silicon. For the same reason, the indentation hardness values of germanium are in the range of 8.0-10.5 GPa [37,38]. Consequently, the hardness values measured in the present work correspond to literature data.…”

Section: Mechanical Properties Of Filler Alloysupporting

confidence: 85%

Development of Rapidly-Quenched Al-Ge-Si Filler Alloys for the Joining of Stainless Steel AISI 304 and Aluminum Alloy AA6082

Ivannikov

Fedorov

Abramov

et al. 2021

Metals

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Aluminum alloys based on the Al-Ge-Si system with a germanium content of up to 40 wt.%, promising for the brazing of aluminum alloy AA6082 with the stainless steel AISI 304, were studied. The temperature characteristics and microstructural and mechanical properties of the filler alloys were systematically investigated. Differential scanning calorimetry showed that with an increase in the germanium content from 28.0 to 40.0 wt.%, the liquidus temperature of the filler alloys decreased from 514.8 to 474.3 °C. X-ray diffraction analysis and electron microscopy data showed that the foil of the filler alloys reveals a homogeneous structure. The ingots of the alloys contain two eutectics, the first of which consists of a solid solution of (Al, Ge) with a solid solution of (Ge, Si), and the second consists of a solid solution of (Al, Ge) with a solid solution based on (Ge). When the content of germanium increases from 28.0 to 40.0 wt.%, a separation of the faceted solid solution particles (Ge, Si) and an increase in their number could be observed. Nanohardness measurements showed that the (Ge, Si) and (Ge) solid solutions had similar nanohardness, with values of 11.6 and 10.2 GPa, respectively. Simultaneously, the Al solid solution and the intermetallic Al7Ge2Fe phase exhibited significantly lower nanohardness values of 0.7 and 6.7 GPa, respectively. Brinell hardness measurements showed that the ingots of the filler alloys were sufficiently ductile and had a hardness comparable to that of AA6082, which is used for brazing with AISI 304 stainless steel. The obtained results for the studied ingots and the rapidly quenched foils can be used to predict the forming structure of the seam after brazing and adjusted for diffusion processes occurring between the brazed materials and the studied filler alloys.

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Section: Mechanical Properties Of Filler Alloysupporting

confidence: 85%

Development of Rapidly-Quenched Al-Ge-Si Filler Alloys for the Joining of Stainless Steel AISI 304 and Aluminum Alloy AA6082

Ivannikov

Fedorov

Abramov

et al. 2021

Metals

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“…Formation of nanocrystalline BC8 regions was also observed in nano-grinding experiments, 70 in SiGe epilayers, 71 and in nanoindentation experiments. [72][73][74][75] Recently, even direct colloidal synthesis of BC8 nanoparticles was reported, which would completely bypass the need for high pressure synthesis. 76 These experiments suggest that Si NPs with core structures based on high pressure Si phases are promising candidates to exhibit a lower gap than Si-I NPs and low energy optical absorption, especially the BC8 phase, which is gapless in the bulk.…”

Section: B Embedded Si Nanoparticlesmentioning

confidence: 99%

Novel silicon phases and nanostructures for solar energy conversion

Wippermann

Vörös

et al. 2016

Applied Physics Reviews

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Silicon exhibits a large variety of different bulk phases, allotropes, and composite structures, such as, e.g., clathrates or nanostructures, at both higher and lower densities compared with diamond-like Si-I. New Si structures continue to be discovered. These novel forms of Si offer exciting prospects to create Si based materials, which are non-toxic and earth-abundant, with properties tailored precisely towards specific applications. We illustrate how such novel Si based materials either in the bulk or as nanostructures may be used to significantly improve the efficiency of solar energy conversion devices.

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“…Equation ( 4) relies on the calculation of the elastic stress, and plastic deformation is assumed to take place when the elastic stress reaches the value of the yield stress. Thus equation (4) does not take into account possible phase transformations in Si [66][67][68] , but since such transformations would take place under both the nanoindenter and the AFM, our qualitative conclusion from Figure 4 still holds. Equation (4) also does not account for a nanoindentationsize effect, but as shown in Figure S1b, this effect is small in our experiments.…”

Section: 𝑅 = 𝑊𝑥 𝑉mentioning

confidence: 86%

Size Dependence of Nanoscale Wear of Silicon Carbide

Tangpatjaroen

Grierson

Shannon

et al. 2017

ACS Appl. Mater. Interfaces

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Nanoscale, single-asperity wear of single-crystal silicon carbide (sc-SiC) and nanocrystalline silicon carbide (nc-SiC) is investigated using single-crystal diamond nanoindenter tips and nanocrystalline diamond atomic force microscopy (AFM) tips under dry conditions, and the wear behavior is compared to that of single-crystal silicon with both thin and thick native oxide layers. We discovered a transition in the relative wear resistance of the SiC samples compared to that of Si as a function of contact size. With larger nanoindenter tips (tip radius ≈ 370 nm), the wear resistances of both sc-SiC and nc-SiC are higher than that of Si. This result is expected from the Archard's equation because SiC is harder than Si. However, with the smaller AFM tips (tip radius ≈ 20 nm), the wear resistances of sc-SiC and nc-SiC are lower than that of Si, despite the fact that the contact pressures are comparable to those applied with the nanoindenter tips, and the plastic zones are well-developed in both sets of wear experiments. We attribute the decrease in the relative wear resistance of SiC compared to that of Si to a transition from a wear regime dominated by the materials' resistance to plastic deformation (i.e., hardness) to a regime dominated by the materials' resistance to interfacial shear. This conclusion is supported by our AFM studies of wearless friction, which reveal that the interfacial shear strength of SiC is higher than that of Si. The contributions of surface roughness and surface chemistry to differences in interfacial shear strength are also discussed.

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Nanoindentation of Silicon and Germanium

Cited by 9 publications

References 94 publications

Development of Rapidly-Quenched Al-Ge-Si Filler Alloys for the Joining of Stainless Steel AISI 304 and Aluminum Alloy AA6082

Development of Rapidly-Quenched Al-Ge-Si Filler Alloys for the Joining of Stainless Steel AISI 304 and Aluminum Alloy AA6082

Novel silicon phases and nanostructures for solar energy conversion

Size Dependence of Nanoscale Wear of Silicon Carbide

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