Abstract: The present invention relates, a compound for use with selective detectors of the semiconductor resistance type which detect for nitrogenous reducing gases in the atmosphere, especially ammonia and gases containing NH and/or NH.sub.2 groups, said compound comprising the gallium nitride and, oxynitrides of tetrahedral structure according to the general formula: ##EQU1## in which: .quadrature. represents a hole, and 0.ltoreq.x.ltoreq.0.3.

Abstract: The present invention relates to a novel crystalline massive aluminosilicate with an expanded structure and to its process of manufacture. The particular structure is a closed cell structure containing nitrogen. It is obtained by: grinding industrial glass; adding aluminum based nitride in the proportion of 0.1 to 20% by weight with respect to the weight of the ground industrial glass; mixing the ground glass and so-added nitride; oxidizing the nitride within said mixture by heating to a temperature of 800.degree. to 1000.degree. C. for about 1 hour, and cooling and recovering the expanded crystalline aluminosilicate. The material has multiple applications in the building industry and in the construction of furnaces, in the manufacture of fireproof walls and doors, and in naval construction, with various advantages over prior art materials.

Abstract: Nitrides and oxynitrides which can be used as selective detectors of reducing gases in the atmosphere, and a detection device containing them. Selective detectors of nitrogen-containing reducing gases in the atmosphere, in particular ammonia and gases containing NH and/or NH.sub.2 groups, of the semiconductor resistance type, the nitrides and oxynitrides according to the invention are of tetrahedral structure and contain:a metal chosen from the group comprising Li, Na, K, Be, Mg, Ca, Sr, Ba, Zn and Mn;a second element chosen from the group comprising Si, Ge, P, Al and Ga;nitrogen and, if appropriate,oxygen.