Tensile Strengths of Se, As₂S₃, As₂Se₃, and Ge₃₀As₁₅Se₅₅ Glass Fibers

Abstract

The strengths of as‐drawn, abraded, and pristine Se, As2Se3, As2S3, and Ge30As15Se55 fibers are reported. Pristine strength values range from an average of 80 MPa for Se and Ge30As15Se55 to 100 and 180 MPa for As2Se3 and As2S3, respectively. Although these values are considerably higher than those reported previously for bulk samples, in no case does the maximum observed strength reach more than about 6% of that expected from simple theoretial calculations. Several factors that can control the strength are discussed. The overall behavior is interpreted in terms of the glass structures which permit localized stress relaxation effects in regions of weak, nondirectional bonds. These effects occur at temperatures well below the glass‐transition region.

Review of infrared fiber-based components

“…In chalcogenide fibers, commercially delivered fiber is commonly tested to 20 kpsi. Record values remain an order of magnitude below the theoretical expected values, with up to 60 kpsi being reported [2,51]. Fluoride fibers, whose fabricated strength was earlier plagued by the formation of microcrystals [52], now displays record tensile strengths of >90 kpsi for ZBLAN compositions and >50 kpsi for InF [4].…”

Sub-Tg viscoelastic behaviour of chalcogenide glasses, anomalous viscous flow and stress relaxation

“…20) However, chalcogenide glasses show many common features with polymeric molecular organization. McEnroe and LaCourse 28) underline that Se glass "might be expected to exhibit properties closer to those of organic polymers than oxide glasses." Moreover, a-Se has received a large interest in polymer science, constituing one of the "simplest polymers possible" 14) and many authors underline a-Se polymeric-like molecular structure (see 29) for example).…”

“…These two times are closely linked to the structure of a-Se. a-Se contains rings of eight Se atoms 14), 28) which have distorsion under stress conducting to short-time relaxation (S), whereas long-time relaxation (L) is due to the crawling of polymeric versus Ln(t) for KWW fit. Example of GeSe4.…”

Long-term physical ageing in As–Se glasses with short chalcogen chains

“…So a thermodynamically driven process known as physical ageing occurs in freshly drawn Se-based optical fibres, tending them to the equilibrium state of undercooled liquid. This is the reason for the structural metastability of ChGs, which can lead to time dependent instability in their mechanical properties [3,4]. Even thermal annealing near the glass transition temperature T g does not resolve this problem completely, due to very slow relaxation.…”

“…High transparency in the IR spectral region makes AsSe chalcogenide glasses (ChGs) one of the most promising materials for optoelectronics and IR-fibre optics [1][2][3][4]. The fibres drawn for such applications undergo rapid quenching, which introduces a high excess configurational entropy, enthalpy or free volume over the thermodynamic equilibrium state of undercooled liquid [5,6].…”