A method of preparing a metal nitride andor metal oxynitride particulate material includes heating a stoichiometric mixture of a metal compound and urea at a temperature of about 400-1000\xb0 C. The body includes an upper panel and a side skirt extending outwardly away from the upper panel to define a free edge opposite the upper panel. In the stored position, the platform is folded to overlie the parallelogram linkage.