TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The crystal phase content is 10-80 (preferably 20-70) vol.%. (I) has a p-type or n-type dopant. (I) has a doped perovskite phase, preferably a perovskite phase having strontium titanate (SrTiO3) structure. The perovskite phase is doped with: fluorine at the oxygen side; at least one dopant at strontium site, where the dopant is lanthanum ion (La3+), yttrium ion (Y3+), cerium ion (Ce3+), praseodymium ion (Pr3+), neodymium ion (Nd3+), samarium ion (Sm3+), europium ion (Eu3+), gadolinium ion (Gd3+), terbium ion (Tb3+), dysprosium ion (Dy3+), holmium ion (Ho3+), erbium ion (Er3+), thulium ion (Tm3+), ytterbium ion (Yb3+) or lutetium ion (Lu3+); at least one dopant at titanium site, where the dopant is vanadium, niobium or tantalum; at least one dopant at strontium site, where the dopant is potassium, sodium or rubidium; at least one dopant at oxygen site, where the dopant is nitrogen or phosphorus; or at least one dopant at titanium site, where the dopant is scandium, aluminum, boron, iron, chromium, nickel, cobalt, manganese or copper. The ceramic glass has 5-30 mol.% of a glass former, preferably 5-10 mol.% of at least two-components, which are silicon dioxide (preferred), aluminum trioxide, boron trioxide or phosphorus pentoxide. (I) comprises: 20-60 mol.% of at least one component, which is titanium dioxide, zirconium oxide or hafnium dioxide; and 0.1-20 mol.% of at least one dopant, which is niobium pentoxide, vanadium pentoxide or tantalum pentoxide. The main crystalline phase contains a strontium-niobium-titanium oxide compound of formula (SrNbxTi1-xO3). (I) comprises (in wt.%, based on oxide): silicon dioxide (5-30, preferably 5-20); aluminum trioxide (3-20, preferably 5-15); boron trioxide (0-20); phosphorus pentoxide (0-20); strontium oxide (0-60, preferably 20-50); barium oxide (0-60, preferably 0-50); titanium dioxide (5-60, preferably 20-50); and niobium pentoxide (1-20, preferably 3-15), where the sum of strontium oxide and barium oxide is at least 5 wt.%. EXAMPLE - Silicon dioxide (11.4 wt.%), aluminum trioxide (7.6 wt.%), titanium dioxide (36 wt.%), niobium pentoxide (6 wt.%) and strontium oxide (39 wt.%) were melted at 1500-1600 degrees C. After the fining and homogenizing, glass was added in thin rod form. Then the glass was ceramized at 850-950 degrees C for 3 minutes to form ceramic glass having amorphous phase (69 wt.%) and strontium titanate phase (31 wt.%).