A method for producing sulfide-based glass ceramics including crystallizing a glass solid electrolyte, wherein the glass solid electrolyte includes: sulfide-based glass comprising at least a sulfur element and a lithium element; and a nitrile compound incorporated into the sulfide-based glass.

Provided is a photochromic substance that has lower toxicity, exhibits good sensitivity in a visible light region, changes color deeply, has slow speed of color fading, has chemical and thermal stability, and has good durability. The photochromic substance has a composition represented by the formula:
Ba.sub.(a-b)Ca.sub.bMg.sub.cSi.sub.dO.sub.e:Fe.sub.fM.sub.gM.sub.h where 1.8a2.2, 0b0.1, 1.4c3.5, 1.8d2.2, e=(a+c+2d), 0.0001f, 0.0001g, 0h, M is at least one of Al and Eu, and M is at least one element selected from the group consisting of Na, K, Nd, Li, S, C, Ti, V, Mn, Cr, Cu, Ni, Co, Ge, Zn, Ga, Zr, Y, Nb, In, Ag, Mo, Sn, Sb, Bi, Ta, W, La, Ce, Pr, Nd, Sm, Gd, Er, Ho, Tb, Tm, Yb, Lu, P, Cd, and Pb.

A method of manufacturing a glass-phosphor composite is disclosed. The method comprises: preparing rare earth ion-containing parent glass; mixing the rare-earth ion-containing parent glass in a power state with a phosphor in a powder state; and providing a glass-phosphor composite using the powder mixture of the rare earth ion-containing parent glass and the phosphor, wherein the mixing includes mixing the rare earth ion-containing parent glass in the powder state with the phosphor in the powder state so that the phosphor in the glass-phosphor composite is in an amount of 5 wt % to 30 wt %, and the preparing includes using a glass frit having a glass transition point of 300 C. to 800 C. and a sintering temperature of 200 C. to 600 C.