A NEW FAMILY OF HIGH SPECIFIC SURFACE-ARE A CHROMIUM OXYNITRIDES - PREPARATION AND CHARACTERIZATION

A new family of high specific surface area chromium oxynitrides : Prep aration and characterization. High specific surface area chromium oxyn itride powders (Sg > 100 m(2).g(-1)) have been synthesized from a reac tive chromium hydroxide precursor prepared by precipitation in hydroal coholic medium. The nitridation of the precursor at low temperatures i n flowing ammonia leads to a series of NaCl type chromium oxynitrides without any crystallization of alpha-Cr2O3. The composition, the state of crystallization and the Sg values of the nitrided phases closely d epend on the nitridation temperature and time.