Fundamentals of Cr and Fe Atomic Defects Formation in Nonstoichiometric ZnS Crystals for Infrared Lasers

Abstract

Using the method of graphical thermodynamics and information about T‐X projections of binary and quasi‐binary systems, 76 isothermal cross‐sections are constructed in the temperature range 300–2500 K for the Zn‐S‐Fe system and 75 isothermal cross‐sections in the temperature range 300–2700 K for the Zn‐S‐Cr system from complete melting of the system to the state when the liquid phase in the entire concentration triangle has ceased to exist. The monovariant equilibria of the Zn‐S‐Fe/Cr ternary systems are studied by high‐temperature annealing in silica ampoules followed by quenching. The synthesized samples are investigated using X‐ray diffraction analysis, which confirms the presence of phases participating in these equilibria and the correctness of the constructed cross‐sections. In the ternary systems under study, it is assumed that there are 18 nonvariant and 39 monovariant equilibria for the Zn‐S‐Fe system, 35 nonvariant and 45 monovariant equilibria for the Zn‐S‐Cr system. The information obtained can be used to improve the technology of IR lasers based on active elements ZnS:Cr and ZnS:Fe.