Effects of sonication and cavitation pretreatments on diamond nucleation without diamond seeding

Abstract

Diamond nucleation on the substrates pre-treated by sonication and cavitation effects without diamond seeding methods by microwave plasma chemical vapor deposition can increase the diamond nucleation density by more than three to four orders magnitude from that of non-treated substrates In order to do the experiment of sonication and cavitation effects choosing water alcohol Ethylene Glycol for cavitation and Mo powder W powder SiO2 flakes for sonication to test the effects by those methods is the key step for the substrate pretreatments Diamond nucleation of the water cavitation pretreatment samples which are first sputtered chromium thin film then sputtered MoCu thin film can make the diamond nucleation density exceed ?10?^8 ? cm?^(-2) besides sonication pretreatment samples can reach about ?10?^7 ? cm?^(-2) Surface roughness treated by the sonication effect is greater than the cavitation effect but the greater the surface roughness it does not necessarily have a higher nucleation density

Date of Award	2020
Original language	English
Supervisor	Yon-Hua Tzeng (Supervisor)