Crystal growth and thermal annealing of AgGaGe5Se12 crystal

Highlights: • AgGaGe₅Se₁₂ polycrystalline materials have been synthesized. • AgGaGe₅Se₁₂ single crystals with Φ30 mm × 50 mm have been obtained. • We have discussed the relationship between structure and physicochemical. • The absorptions at 3.4 and 7 µm have been eliminated after annealing. -- Abstract: AgGaGe₅Se₁₂ is a new quaternary nonlinear optical crystal which is applied to laser frequency conversion, especially converting 1.064 µm light to mid-IR range. In this work, we have synthesized the AgGaGe₅Se₁₂ polycrystal by the two-zones temperature method. By the modified Bridgman method, we have grown high-quality AgGaGe₅Se₁₂ single crystal 30 mm in diameter and 50 mm in length. The structure refinement was carried out by the Rietveld method. Besides, the XRS results were analyzed by comparing with AgGaGeS₄ and AgGaGe₅S₁₂. In addition, the non-polarized Raman spectra were recorded and the intense peaks were observed at 200 and 232 cm⁻¹. The peaks were attributed to corner-sharing (CS) and edge-sharing (ES) clusters. At last, the crystal was characterized by a high transparency in the 0.6–15 µm spectral range and the absorptions at 3.4 and 7 µm, observed in the as-grown crystal, have been eliminated after annealing. Thus, AgGaGe₅Se₁₂ is appropriate for further optical experiments and more comprehensive applications.