Abstract: A boron and silicon oxynitride obtained by preparing a polyborosiloxane precursor, conducting nitriding pyrolysis of the precursor to obtain an amorphous boron and silicon oxynitride, and optionally conducting additional pyrolysis to obtain a crystallized boron and silicon oxynitride. The polyborosiloxane precursor is prepared by condensation, in the presence of a catalyst, of (2) a polychlorosilane represented by the formula R3R4SiCl2 in which the substituents R3 and R4 are identical or different and each represents a hydrogen atom, a chlorine atom, a linear or branched alkyl or alkenyl or alkynyl radical having 5 or less carbon atoms, or an aryl or aralkyl radical having 6 to 18 carbon atoms, with (2) an alkyl borate represented by the formula (R5O)3B in which R5 represents a linear or branched alkyl radical having 1 to 5 carbon atoms.

Abstract: The present invention relates to new conductive perovskites containing oxygen and nitrogen, their preparation and their use particularly as electrode material.The conductive perovskites containing oxygen and nitrogen according to the invention correspond to the general formula IAB(O,N).sub.3 (I)in the cationic lattice of which:A denotes a metal chosen from the metals of groups IA and IIA, yttrium and the lanthanides,B denotes a metal chosen from the transition metals of groups IVA to IB,on the express condition that at least one of the metals A and B is present in an oxidation state other than its normal maximum oxidation state.