Patent ID: 8679996

Claim:
A method for manufacturing an optoceramic having crystallites of the formula A x C u B y D v E z F w , whereby A and C are selected from the group consisting of Li + , Na + , Be 2+ , Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ , Al 3+ , Ga 3+ , In 3+ , C 4+ , Si 4+ , Ge 4+ , Sn 2+/4+ , Sc 3+ , Ti 4+ , Zn 2+ , Zr 4+ , Mo 6+ , Ru 4+ , Pd 2+ , Ag 2+ , Cd 2+ , Hf 4+ , W 4+/6+ , Re 4+ , Os 4+ , Ir 4+ , Pt 2+/4+ , Hg 2+ and mixtures thereof, B and D are selected from the group consisting of Li + , Na + , K + , Mg 2+ , Al 3+ , Ga 3+ , In 3+ , Si 4+ , Ge 4+ , Sn 4+ , Sc 3+ , Ti 4+ , Zn 2+ , Y 3+ , Zr 4+ , Nb 3+ , Ru 3+ , Rh 3+ , La 3+ , Lu 3+ , Gd 3+ and mixtures thereof, E and F are selected mainly from the group consisting of the divalent anions of S, Se and O and mixtures thereof, x, u, y, v, z and w satisfy the following formulae 0.125<( x+u )/( y+v )≦0.55 z+w= 4 and at least 95% by weight of said crystallites display symmetric, cubic crystal structures of the spinel type, with the proviso that when A=C=Mg 2+ and B=D=Al 3+ , E and F cannot both be O, which comprises the following steps: (1) production of a homogeneous powder mixture by mixing powder raw materials having an average primary particle diameter of 20 nm to 1 μm in accordance with a desired composition, optionally with addition of additives such as binders, sintering aids and dispersants in a solvent to form a slurry and drying said slurry to give a powder, (2) production of a preform from said powder obtained in step (1), (3) optionally burning-out of any dispersants and binders present from said preform at temperatures of 500 to 900° C., (4) sintering said preform at temperatures of 1400 to 1900° C. to obtain an optoceramic, (5) optionally pressure sintering said optoceramic obtained in step (4) at 1400 to 2000° C. under a pressure of 10 to 300 MPa, and (6) optionally oxidation of said optoceramic obtained in step (4) or (5) in a stream of O 2 at temperatures of up to 1000° C. for 5 to 10 hours in order to remove any discoloration which may occur.