The phase equilibria in the Er2S3–In2S3–Ga2S3 quasi-ternary system at 770 ​K and the properties of the intermediate compounds

The quasi-ternary systems Er2S3–In2S3–Ga2S3 was investigated by X-ray method, the isothermal section of the system at 770 ​K was constructed. Using X-ray structure analysis the crystal structures of the new compounds Ga2.78In3.88Y3.35S15 (I), Ga2.98In2.66Er4.37S15 (II), Ga3.37In1.26Tm5.37S15 (III), Ga3.46In1.58Yb4.96S15 (IV) were calculated. They crystallize in the space group C2/m with lattice parameters: a ​= ​23.4104(6) Å, b ​= ​3.81242(12) Å, c ​= ​12.5460(4) Å, β ​= ​90.775(3)° (I); a ​= ​23.5181(17) Å, b ​= ​3.8064(3) Å, c ​= ​12.5592(9) Å, β ​= ​90.954° (II); a ​= ​23.5474(8) Å, b ​= ​3.78634(15) Å, c ​= ​12.5164(4) Å, β ​= ​90.988(3)° (III), a ​= ​23.4427(7) Å, b ​= ​3.77641(8) Å, c ​= ​12.4970(3) Å, β ​= ​90.970° (IV). The photoluminescent spectra of the (Ga54.59In44.66Er0.75)2S300 single crystal were investigated. With the decreasing of the temperature till 300, 250, 200, 150 ​K the intensity of the photoluminescent spectra decreases. The position and shape of the spectra do not change according to the temperature decreasing. The maximum of the photoluminescent spectra (0.81 ​eV) corresponds to the transitions 4І13/2 ​→ ​4I15/2 in the f-shell of Er3+ ions. [Display omitted] •Ga2.78In3.88Y3.35S15, Ga2.98In2.66Er4.37S15, Ga3.37In1.26Tm5.37S15, Ga3.46In1.58Yb4.96S15 structures were studied.•The isothermal section of Er2S3–In2S3–Ga2S3 at 770 ​K was built based on XRD and MSA of the samples.•The PL spectra of the single crystal (Ga54.59In44.66Er0.75)2S300 were investigated at different temperatures (980 ​nm).