Peculiarities of GaxGe100-x-ySey glasses crystallization as potential materials for optical IR glass-ceramics

•Crystallization of GaxGe100-x-ySey (x = 0–30; y = 60–75) glasses was studied.•Crystalline phases, formed during the GaxGe100-x-ySey glass crystallization, are found.•A distinctive feature of the crystallization of GaxGe100-x-ySey glasses is the formation of globules.•Among the studied compositions, glasses with a Se content of 60 at.% and Ga content up to 15 at.% are optimum for the preparation of IR glass-ceramic materials.