Alumina atomic layer deposition nanocoatings on primary diamond particles using a fluidized bed reactor

Ultra-thin alumina films are successfully deposited on primary micron-sized diamond particles in a scalable fluidized bed reactor. The studies of fluidization at reduced pressure show that micron-sized diamond particles can be fluidized with the assistance of vibration. Alumina films are grown at 177 °C by atomic layer deposition (ALD) using sequential exposures of Al(CH3)3 and H2O. The deposited alumina films are characterized by X-ray photoelectron spectroscopy, transmission and scanning electron microscopy, inductively coupled plasma-atomic emission spectroscopy, and surface area. The results indicate that the alumina films are conformally coated on the primary diamond particle surface, and the growth rate of alumina is 0.12 nm per coating cycle.