Sk. Singhal et al., On catalytic action of nickel, copper and nickel-copper alloy in graphite-diamond phase transformation, I J PA PHYS, 39(3), 2001, pp. 163-169
Synthetic diamonds were grown by subjecting spectroscopic grade graphite to
static high pressures and temperatures in the presence of copper, nickel a
nd their alloy namely monel as catalyst solvents. Diamond formation in the
presence of conventional catalysts (nickel and monel) takes place immediate
ly after their melting temperatures. However, the catalytic action of coppe
r was found to be altogether different from the well known iron group metal
s and alloys (nickel and monel) in that it is found to be inert with graphi
te near its melting temperature, however at much higher temperature it beco
mes an active catalyst and leads to diamond formation. The graphite-diamond
phase transformation in presence of these catalysts is discussed based on
experimental evidences.