Crystallization of AgGaS₂ melts enriched with Ag₂S and Ga₂S₃

Abstract

In this work we consider experiments with directed crystallization of melts with slight deviation from stoichiometric composition of AgGaS 2 . The evolution of melt composition was calculated for both experiments using measured chemical composition of the solid phase. Also the difference in unit cell parameters and luminescence spectra for AgGaS 2 grown from the melts was found. Both monocrystal samples and samples synthesized from elementary Ag, Ga and S were used for thermal analyses. Obtained data suggests that different ways of preparing the samples are responsible for defects concentration and thus for so wide range (70°C) of melting temperatures reported in scientific literature.

Growth of GaSe and GaS single crystals

“…Though small quantities of chalcogenides may be prepared by direct fusion of starting components (e.g. AgGaS 2 [11], ZnGeP 2 [12]), for large amounts of material it is more convenient to use two-temperature (or two-zone) method [13][14][15]. In this method, an elongated ampoule with more and less volatile components in the opposite sides is heated in horizontal two-zone furnace.…”

Core level photoelectron spectroscopy of LiGaS2 and Ga–S bonding in complex sulfides

“…Within the past few years many binary and ternary sulfide systems were evaluated in searching for new compounds with noncentrosymmetric crystal structure and nonlinear optical (NLO) properties [2][3][4][5][6][7][8][9][10][11][12]. Among known crystals several binary and ternary thiogallates are showing high level of NLO susceptibility and pronounced ability for solid solution formation necessary for accurate tuning of optical properties by doping [1][2][3]5,7,[13][14][15][16][17].…”

Non-stoichiometry and point native defects in non-oxide non-linear optical large single crystals: advantages and problems

“…From the 1970s, much activity was directed to studying phase equilibrium in the Ag 2 S–Ga 2 S 3 system using DTA, XRD, metallographic analysis, and optical and thermal characteristics of crystals. 4–7 The general view of T – X diagrams at the microscale was presented by several authors, where the AGS single-phase field looked speculative owing to the lack of experimental points on the Ag 2 S and Ga 2 S 3 solidus lines. 5,7,8 Due to low sensitivity of the used techniques, it was impossible to detect precisely boundaries between single- and two-phase states of the test samples.…”

“…4–7 The general view of T – X diagrams at the microscale was presented by several authors, where the AGS single-phase field looked speculative owing to the lack of experimental points on the Ag 2 S and Ga 2 S 3 solidus lines. 5,7,8 Due to low sensitivity of the used techniques, it was impossible to detect precisely boundaries between single- and two-phase states of the test samples. 5 Nevertheless, it was established that AGS is a phase of variable composition with the left phase boundary coinciding with (or very close to) the stoichiometric line, and with the right boundary extending to 51–52 mol% Ga 2 S 3 .…”