Abstract: The main object or purpose of the present invention is to provide a glass material that is suitable for mold forming, can reduce the size, and allows rays having a wavelength region between visible light to far-infrared light to pass through. To overcome this object, the present invention provides a glass material allowing rays having a wavelength in the region from visible light to far-infrared light to pass through, the glass material comprising, in terms of molar concentration: 50 to 70% of S, 15 to 30% of Ge, 5 to 20% of Ga, 0.5 to 15% of Ba, and 3 to 15% of at least one member selected from the group consisting of Cl, Br, and I, with the proviso that when the Cl is present alone, the molar concentration is 6 to 15%.

Abstract: The teachings herein are directed at a lithium secondary battery negative electrode active material consisting of a Sn Sb based sulfide that delivers a high electrode capacity density, excellent output characteristics, and excellent cycle life characteristics and also provide a method for manufacturing the lithium secondary battery negative electrode active material, said method being capable of easily manufacturing the high performance lithium secondary battery negative electrode active material at low cost without requiring a high-temperature processing step and special facilities as required in a glass melting method. The negative electrode active material preferably is prepared using a method that includes a step of obtaining a Sn Sb based sulfide precipitate by adding an alkali metal sulfide to a mixed solution of a tin halide and an antimony halide.