LOW-TEMPERATURE THINNING OF THICK CHEMICALLY VAPOR-DEPOSITED DIAMOND FILMS WITH A MOLTEN CE-NI ALLOY

Thinning of chemically vapor-deposited diamond films has been achieved using molten rare earth alloys at substantially lower temperatures th an those previously possible through the use of rare earth elements. A Ce-22%Ni eutectic alloy is shown to reduce the diamond etching temper ature by more than 200 degrees C below the pure rare earth metal's mel ting temperature with no noticeable deterioration in thermal conductiv ity. The molten alloys provide fast reaction kinetics at practical tem peratures (less than 600 degrees C) for industrial application. A larg e number of diamonds may be processed simultaneously in this manner wi thout compromising the material properties of the diamond.