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Devyatykh, G. G.; Dianov, E. M.; Буланов, А. Д.; Troshin, O. Yu.; Balabanov, V. V.; Pryakhin, D. A.

doi:10.1023/a:1025380518197

Cited by 16 publications

(3 citation statements)

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“…During the third technological step the 28 SiF 4 gas was converted into silane, 28 SiH 4 . For the production of high-purity silane the hydride method was used [17]. First, the synthesis of silane was carried out by the reaction of high-purity silicon tetrafluoride with calcium hydride 28 SiF 4 + 2CaH 2 → 28 SiH 4 + 2CaF 2 .…”

Section: Silanisation and Purification Of Silanementioning

confidence: 99%

A new generation of 99.999% enriched²⁸Si single crystals for the determination of Avogadro’s constant

et al. 2017

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A metrological challenge is currently underway to replace the present definition of the kilogram. One prerequisite for this is that the Avogadro constant, N A , which defines the number of atoms in a mole, needs to be determined with a relative uncertainty of better than 2 × 10 −8 . The method applied in this case is based on the x-ray crystal density experiment using silicon crystals. The first attempt, in which silicon of natural isotopic composition was used, failed. The solution chosen subsequently was the usage of silicon highly enriched in 28 Si from Russia. First, this paper reviews previous efforts from the very first beginnings to an international collaboration with the goal of producing a 28 Si single crystal with a mass of 5 kg, an enrichment greater than 0.9999 and of sufficient chemical purity. Then the paper describes the activities of a follow-up project, conducted by PTB, to produce a new generation of highly enriched silicon in order to demonstrate the quasi-industrial and reliable production of more than 12 kg of the 28 Si material with enrichments of five nines. The intention of this project is also to show the availability of 28 Si single crystals as a guarantee for the future realisation of the redefined kilogram.

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Section: Silanisation and Purification Of Silanementioning

confidence: 99%

A new generation of 99.999% enriched²⁸Si single crystals for the determination of Avogadro’s constant

et al. 2017

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Section: Preparation Of Single Crystals and Samples For Measurementsmentioning

confidence: 99%

Refractive index spectral dependence, Raman spectra, and transmission spectra of high-purity Si28, Si29, Si30, and Sinat single crystals

et al. 2011

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“…Polycrystalline silicon was prepared by thermal decomposition of monosilane enriched in one of the silicon isotopes as described in [3,4]. The decomposition was proceed on a graphite substrate surface at 800 • C. After a few mm thick layer was deposited, polycrystalline silicon was separated from the graphite substrate, remelted to form a rod, and purified by 10 float zoning passes.…”

Section: Introductionmentioning

confidence: 99%

Refractive index spectral dependence, Raman and transmission spectra of high-purity $^{28}$Si, $^{29}$Si, $^{30}$Si, and $^{nat}$Si single crystals

Plotnichenko,

Nazaryants,

Kryukova

et al. 2011

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Precise measurement of the refractive index of stable silicon isotopes 28 Si, 29 Si, 30 Si single crystals with enrichments above 99.9 at.% and a silicon single crystal nat Si of natural isotopic composition is performed with the Fourier-transform interference refractometry method from 1.06 to more than 80 µm with 0.1 cm −1 resolution and accuracy of 2 × 10 −5 . . . 1 × 10 −4 . The oxygen and carbon concentrations in all crystals are within 5 × 10 15 cm −3 and the content of metal impurities is 10 −5 . . . 10 −6 at.%. The peculiar changes of the refractive index in the phonon absorption region of all silicon single crystals are shown. The coefficients of generalized Cauchy dispersion function approximating the experimental refractive index values all over the measuring range are given. The transmission and Raman spectra are also studied.

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Cited by 16 publications

References 3 publications

A new generation of 99.999% enriched²⁸Si single crystals for the determination of Avogadro’s constant

A new generation of 99.999% enriched²⁸Si single crystals for the determination of Avogadro’s constant

Refractive index spectral dependence, Raman spectra, and transmission spectra of high-purity Si28, Si29, Si30, and Sinat single crystals

Refractive index spectral dependence, Raman and transmission spectra of high-purity $^{28}$Si, $^{29}$Si, $^{30}$Si, and $^{nat}$Si single crystals

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Cited by 16 publications

References 3 publications

A new generation of 99.999% enriched28Si single crystals for the determination of Avogadro’s constant

A new generation of 99.999% enriched28Si single crystals for the determination of Avogadro’s constant

Refractive index spectral dependence, Raman spectra, and transmission spectra of high-purity Si28, Si29, Si30, and Sinat single crystals

Refractive index spectral dependence, Raman and transmission spectra of high-purity $^{28}$Si, $^{29}$Si, $^{30}$Si, and $^{nat}$Si single crystals

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A new generation of 99.999% enriched²⁸Si single crystals for the determination of Avogadro’s constant

A new generation of 99.999% enriched²⁸Si single crystals for the determination of Avogadro’s constant