a process is provided for fabricating coated particles of a substantially uniform particle size . the process comprises coating small particles of well - defined crystalline phases with a polymerized gel . the process results in a ball - type sol - gel coating of the particles to provide particles which have a narrow size distribution . in many instances , crystalline particles of irregular shape have a substantially spherical shape upon coating with the sol - gel . in instances where the core is a high melting point material , such as an oxide , nitride , or carbide , the coat formulation can effect a low sintering temperature , which permits forming films of the particles at a much lower temperature than would otherwise be possible .