CS263739B1 - Method of production of chalcogenide glass - Google Patents

Abstract

Chalcogenide glasses are characterized by high optical transmittance in the infrared region and are produced by melting glass-forming chalcogen elements from the sulfur, selenium and tellurium group with modifying elements from the germanium, tin, lead, arsenic, antimony and bismuth group, with the mass fraction of the individual components being determined so as to form a ternary or quaternary system of elements. If the system contains germanium, melting temperatures of around 900 °C and higher are achieved. The aim of the solution is to reduce this temperature in order to improve the purity and homogeneity of the chalcogenide glass. The essence is that at least two different binary chalcogenides of the modifying elements are first prepared separately by melting, which are then melted together to form the chalcogenide glass. The melting temperature in the first and second synthesis steps is maintained in the range of 600 to 760 °C.

Description

WACHTL ZDENEK, TURNOV,

MATUSEK MIROSLAV ing. CSc., JABLONEC NAD NISOU

Process for producing chalcogenide glass

Chalcogenide glasses are characterized by high optical transmission in the infrared range and are produced by melting glass-forming chalcogenic elements from the group of sulfur, selenium and tellurium with modifying elements from the group of germanium, tin, lead, arsenic, antimony and bismuth. to create a ternary or quaternary system of elements. If the system contains germanium, it is achieved at melts / temperatures around 900 ° C and higher. The object of the solution is to lower this temperature in order to improve the purity and homogeneity of chalcogenide glass. The principle is that at least two different binary chalcogenides modifying the elements are first prepared separately by melting, which are then remelted together to form chalcogenide glass. The melting point is maintained between 600 and 760 ° C in the first and second synthesis steps.

(52) Int. Cl *

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The invention relates to a process for the production of glass, the glass-forming component of which is one or more chalcogenic elements from the group of sulfur, selenium and tellurium. An important technical feature of chalcogenide glass is its high optical transmission in the infrared range.

However, glass made of chalkogenic elements alone has insufficient mechanical, thermal and chemical properties. Therefore, chalcogenide glass is generally formed from a mixture of chalcogenic. elements and modifying elements of the IV.a and V.a groups of the periodic bite element, mainly of germanium, tin, lead, arsenic, antimony and bisrnut.

The mass representation of chalcogenic and modifying elements is chosen so as to create a temari or quaternary system based on Se-Ge-Asj, Se-Te-Ge-As, Se-Te-Ge-Sb and the like.

The hitherto known process for producing chalcogenide glass consists in melting the selected chalcogenic and modifying elements together in a one-step synthesis process in evacuated ampoules or containers of quartz or other inert materials. The melting has to be carried out at a very high temperature, since the synthesis of said elements takes place at temperatures around 900 ° C and higher. However, at these high temperatures, the quartz is attacked by the melt, which results in the release of the SiO2 particles from the walls of the cogenide glass.

The binary chalcogenides of the modifying elements can be easily purified and deoxidized before proceeding to the second synthesis step by various known physicochemical methods. For example, polycrystalline binary chalcogenides can be purified by zonal melting, while more volatile binary chalcogenides can be purified by distillation, which can be combined and desoxidated if a substance exhibiting a greater chemical affinity for oxygen is added to the distilled material than the individual components of the binary chalcogenide.

Example

Se-Ge-As-based galkalkide glass having a molar composition of 53.3% Se selenium, 33.2% germanium Ge and 13.5% arsenic As was prepared by a two-step synthesis from ASgSe ^ and GeSe. As ^ Se ^ is prepared from the elements As and With melting in an evacuated quartz ampoule at 600 ° C for 12 hours, GeSe is also prepared by melting from the elements in an evacuated quartz ampoule at 700 ° C for 8 hours · Selenides thus obtained arsenic and germanium were mixed in a molar ratio of 0.83 moles GeSe and 0.17 moles ASgSe2 and melted in an evacuated quartz ampoule at 760 ° C for 12 hours. As described above, chalcogenide glass of the above-mentioned composition of high optical purity, without streaks and with a very low micro-heterogeneity content, was prepared. Glass of this quality is usable for the production of passive optical elements.

Claims (1)

SUBJECT OF THE INVENTION A process for the production of chalcogenide glass containing germanium by melting glass-forming chalcogenic elements from the group of sulfur, selenium and tellurium and modifying elements from the group of germanium, tin, lead, arsenic, antimony and bismuth in mass proportion corresponding to the ternary or quaternary system. initially separately prepared by melting at least two different binary chalcogenide modifying elements, which are further remelted together to form chalcogenide glass, wherein the synthesis temperatures of the first and second melting stages are in the range of 600 to 760 ° C.