SELF-PROPAGATING ROUTES TO TRANSITION-METAL PHOSPHIDES

Frictional or thermal initiation (25-550-degrees-C) of a mixture of so dium phosphide (Na3P) and anhydrous transition-metal halides in evacua ted sealed Pyrex or quartz ampoules produces transition-metal phosphid es, sodium chloride and in some cases phosphorus via an exothermic sel f-propagating reaction. The reaction proceeds with a short thermal fla sh (1-2 s) with estimated reaction temperatures in excess of 1000-degr ees-C. The metal phosphides were purified by methanol trituration and characterised by X-ray powder diffraction, SEM, EDXA, magnetic moment measurements, FTIR, microanalysis and solid-state P-31 NMR.