1：Experimental Design and Method Selection:

The study involved synthesizing ZGSe polycrystals using a double-zone furnace method to control pressure and prevent ampoule explosion, followed by characterization of optical, thermal expansion, and thermal conductivity properties. Theoretical models included phase diagram analysis and thermal shock resistance calculations.

2：Sample Selection and Data Sources:

Samples were synthesized from pure elements (Zn, Se, Ga with 5N purity) in sealed silica reactors under vacuum. Data were obtained from XRD, optical transmission measurements, thermal conductivity, and thermal expansion tests.

3：List of Experimental Equipment and Materials:

Equipment included a double-zone furnace, PANalytic X'Pert PRO diffractometer for XRD, Varian Agilent Cary 6000i and FTIR Nicolet 5700 for optical transmission, C-Therm TCI TH130041 for thermal conductivity, and Setaram Setsys Evolution for thermal expansion. Materials were pure Zn, Se, Ga elements.

4：Experimental Procedures and Operational Workflow:

Synthesis involved heating to 1150°C at 0.5°C/min, soaking for 24h, cooling to 800°C at 0.2°C/min, and then to room temperature at 5°C/min. Samples were polished for measurements; XRD identified phases, optical transmission was measured from 0.5 to 20 μm, thermal conductivity was measured using MTPS method, and thermal expansion was measured under argon atmosphere.

5：5°C/min, soaking for 24h, cooling to 800°C at 2°C/min, and then to room temperature at 5°C/min. Samples were polished for measurements; XRD identified phases, optical transmission was measured from 5 to 20 μm, thermal conductivity was measured using MTPS method, and thermal expansion was measured under argon atmosphere. Data Analysis Methods:

5. Data Analysis Methods: XRD patterns were compared with ICDD records, optical losses were analyzed from transmission spectra, thermal conductivity was calculated with 5% accuracy, and thermal expansion coefficient was derived from length changes with temperature using equation (1).